function validateUSPhone( strValue ) {
/************************************************
DESCRIPTION: Validates that a string contains valid
  US phone pattern. 
  Ex. (999) 999-9999 or (999)999-9999
  
PARAMETERS:
   strValue - String to be tested for validity
   
RETURNS:
   True if valid, otherwise false.
*************************************************/
  var objRegExp  = /^\([1-9]\d{2}\)\d{3}\-\d{4}$/;
//  var objRegExp  = /^\([1-9]\d{2}\)\s?\d{3}\-\d{4}$/; 
//remove possibility of space.
  //check for valid us phone with or without space between 
  //area code
  return objRegExp.test(strValue); 
}

function validateUSDate( strValue ) {
/************************************************
DESCRIPTION: Validates that a string contains only 
    valid dates with 2 digit month, 2 digit day, 
    4 digit year. Date separator can be ., -, or /.
    Uses combination of regular expressions and 
    string parsing to validate date.
    Ex. mm/dd/yyyy or mm-dd-yyyy or mm.dd.yyyy
    
PARAMETERS:
   strValue - String to be tested for validity
   
RETURNS:
   True if valid, otherwise false.
   
REMARKS:
   Avoids some of the limitations of the Date.parse()
   method such as the date separator character.
*************************************************/
  var objRegExp = /^\d{2}(\/)\d{2}\1\d{4}$/
  //var objRegExp = /^\d{1,2}(\-|\/|\.)\d{1,2}\1\d{4}$/
// allow only the / as the separator and 2 digits only
 
  //check to see if in correct format
  if(!objRegExp.test(strValue))
    return false; //doesn't match pattern, bad date
  else{
    var arrayDate = strValue.split(RegExp.$1); //split date into month, day, year
	var intDay = parseInt(arrayDate[1],10); 
	var intYear = parseInt(arrayDate[2],10);
    var intMonth = parseInt(arrayDate[0],10);
	
	//check for valid month
	if(intMonth > 12 || intMonth < 1) {
		return false;
	}
	
    //create a lookup for months not equal to Feb.
    var arrayLookup = { '01' : 31,'03' : 31, '04' : 30,'05' : 31,'06' : 30,'07' : 31,
                        '08' : 31,'09' : 30,'10' : 31,'11' : 30,'12' : 31}
  
    //check if month value and day value agree
    if(arrayLookup[arrayDate[0]] != null) {
      if(intDay <= arrayLookup[arrayDate[0]] && intDay != 0)
        return true; //found in lookup table, good date
    }
		
    //check for February
	var booLeapYear = (intYear % 4 == 0 && (intYear % 100 != 0 || intYear % 400 == 0));
    if( ((booLeapYear && intDay <= 29) || (!booLeapYear && intDay <=28)) && intDay !=0)
      return true; //Feb. had valid number of days
  }
  return false; //any other values, bad date
}

/* 
   This is the source code for the validation function. You can copy and paste 
   the contents in to a file, say, gen_validation.js .
   Add the following code just after the </HEAD> in the files where the 
   generalised validation functionality is required. 
   <SCRIPT language="JavaScript1.2" src="gen_validation.js"></SCRIPT> 

   The next two pages gives examples on using the funcions. 

*/ 

   /* 
   *   File : gen_validation.js 
   *     
   *   Author : Prasanth M J 
   * 
   *   Published at 
   *   CreativeProgrammers.com - The technical knowledge repository. 
   *   http://www.creativeprogrammers.com 
   *     
   *     
   */ 
//---------------------------------EMail Check ------------------------------------ 

/*  checks the validity of an email address entered 
*   returns true or false 
*   
*/ 

function validateEmail(email)
{
// a very simple email validation checking. 
// you can add more complex email checking if it helps 
   var splitted = email.match("^(.+)@(.+)$");
   if(splitted == null) return false;
   if(splitted[1] != null )
   {
     var regexp_user=/^\"?[\w-_\.]*\"?$/;
     if(splitted[1].match(regexp_user) == null) return false;
   }
   if(splitted[2] != null)
   {
     var regexp_domain=/^[\w-\.]*\.[A-Za-z]{2,4}$/;
     if(splitted[2].match(regexp_domain) == null) 
     {
       var regexp_ip =/^\[\d{1,3}\.\d{1,3}\.\d{1,3}\.\d{1,3}\]$/;
       if(splitted[2].match(regexp_ip) == null) return false;
     }// if
     return true;
   }
return false;
}

/* function validateData 
*  Checks each field in a form 
*  Called from validateForm function 
*/ 
function validateData(strValidateStr,objValue,strError) 
{ 
   var epos = strValidateStr.search("="); 
   var  command  = ""; 
   var  cmdvalue = ""; 
   if(epos >= 0) 
   { 
    command  = strValidateStr.substring(0,epos); 
    cmdvalue = strValidateStr.substr(epos+1); 
   } 
   else 
   { 
    command = strValidateStr; 
   } 

   switch(command) 
   { 
       case "req": 
       case "required": 
        { 
          if(eval(objValue.value.length) == 0) 
          { 
             if(!strError || strError.length ==0) 
             { 
               strError = objValue.name + " : Required Field"; 
             }//if 
             alert(strError); 
             return false; 
          }//if 
          break;             
        }//case required 
       case "maxlength": 
       case "maxlen": 
         { 
            if(eval(objValue.value.length) >  eval(cmdvalue)) 
            { 
              if(!strError || strError.length ==0) 
              { 
                strError = objValue.name + " : "+cmdvalue+" characters maximum "; 
              }//if 
              alert(strError + "\n[Current length = " + objValue.value.length + " ]"); 
              return false; 
            }//if 
            break; 
         }//case maxlen 
       case "minlength": 
       case "minlen": 
          { 
            if(eval(objValue.value.length) <  eval(cmdvalue)) 
            { 
              if(!strError || strError.length ==0) 
              { 
                strError = objValue.name + " : " + cmdvalue + " characters minimum  "; 
              }//if               
              alert(strError + "\n[Current length = " + objValue.value.length + " ]"); 
              return false;                 
            }//if 
            break; 
           }//case minlen 
       case "alnum": 
       case "alphanumeric": 
          { 
             var charpos = objValue.value.search("[^A-Za-z0-9]"); 
             if(objValue.value.length > 0 &&  charpos >= 0) 
             { 
              if(!strError || strError.length ==0) 
               { 
                 strError = objValue.name+": Only alpha-numeric characters allowed "; 
               }//if 
               alert(strError + "\n [Error character position " + eval(charpos+1)+"]"); 
               return false; 
             }//if 
             break; 
          }//case alphanumeric 
       case "num": 
       case "numeric": 
          { 
             var charpos = objValue.value.search("[^0-9]"); 
             if(objValue.value.length > 0 &&  charpos >= 0) 
             { 
               if(!strError || strError.length ==0) 
               { 
                 strError = objValue.name+": Only digits allowed "; 
               }//if               
               alert(strError + "\n [Error character position " + eval(charpos+1)+"]"); 
               return false; 
             }//if 
             break;               
          }//numeric 
       case "alphabetic": 
       case "alpha": 
          { 
             var charpos = objValue.value.search("[^A-Za-z]"); 
             if(objValue.value.length > 0 &&  charpos >= 0) 
             { 
                 if(!strError || strError.length ==0) 
               { 
                 strError = objValue.name+": Only alphabetic characters allowed "; 
               }//if                             
               alert(strError + "\n [Error character position " + eval(charpos+1)+"]"); 
               return false; 
             }//if 
             break; 
          }//alpha 
       case "email": 
         { 
              if(!validateEmail(objValue.value)) 
              { 
                if(!strError || strError.length ==0) 
                { 
                   strError = objValue.name+": Enter a valid Email address "; 
                }//if                                               
                alert(strError); 
                return false; 
              }//if 
          break; 
         }//case email 
       case "lt": 
       case "lessthan": 
        { 
           if(isNaN(objValue.value)) 
           { 
             alert(objValue.name+": Should be a number "); 
             return false; 
           }//if 
           if(eval(objValue.value) >=  eval(cmdvalue)) 
           { 
             if(!strError || strError.length ==0) 
             { 
               strError = objValue.name + " : value should be less than "+ cmdvalue; 
             }//if               
             alert(strError); 
             return false;                 
            }//if             
           break; 
        }//case lessthan 
       case "gt": 
       case "greaterthan": 
        { 
           if(isNaN(objValue.value)) 
           { 
             alert(objValue.name+": Should be a number "); 
             return false; 
           }//if 
            if(eval(objValue.value) <=  eval(cmdvalue)) 
            { 
              if(!strError || strError.length ==0) 
              { 
                strError = objValue.name + " : value should be greater than "+ cmdvalue; 
              }//if               
              alert(strError); 
              return false;                 
            }//if             
           break; 
        }//case greaterthan 
       case "regexp": 
        { 
           if(!objValue.value.match(cmdvalue)) 
           { 
             if(!strError || strError.length ==0) 
             { 
               strError = objValue.name+": Invalid characters found "; 
             }//if                                                               
             alert(strError); 
             return false;                   
           }//if 
          break; 
        }//case regexp 
       case "dontselect": 
        { 
           if(objValue.selectedIndex == null) 
           { 
             alert("BUG: dontselect command for non-select Item"); 
             return false; 
           } 
           if(objValue.selectedIndex == eval(cmdvalue)) 
           { 
            if(!strError || strError.length ==0) 
             { 
             strError = objValue.name+": Please Select one option "; 
             }//if                                                               
             alert(strError); 
             return false;                                   
            } 
            break; 
        }//case dontselect 
	  case "dec": 
      case "decimal": 
       { 
          var charpos = objValue.value.search("[^0-9.]"); 
          if(objValue.value.length > 0 && charpos >= 0) 
          { 
            if(!strError || strError.length ==0) 
            { 
              strError = objValue.name+": Only digits and a decimal allowed "; 
            }//if 
            alert(strError + "\n [Error character position " + eval(charpos+1)+"]"); 
            return false; 
          }//if 
          break; 
       }//decimal 
     case "mdate": 
         { 
              if(!validateUSDate(objValue.value)) 
              { 
                if(!strError || strError.length ==0) 
                { 
                   strError = objValue.name+": Enter a valid Date"; 
                }//if                                               
                alert(strError); 
                return false; 
              }//if 
          break; 
         }//case date		
     case "phone": 
         { 
              if(!validateUSPhone(objValue.value)) 
              { 
                if(!strError || strError.length ==0) 
                { 
                   strError = objValue.name+": Enter a valid Phone"; 
                }//if                                               
                alert(strError); 
                return false; 
              }//if 
          break; 
         }//case date		
		
		
   }//switch 
   return true; 
} 

/* 
* function validateForm 
* the function that can be used to validate any form 
* returns false if the validation fails; true if success 
* arguments : 
*   objFrm     : the form object 
*   arrObjDesc : an array of objects describing the validations to conduct on each 
*        input item. 
*          The array should consist of one object per input item in the order the input 
*          elements are present in the form. Each object consist of zero or more validation 
*          objects. Each of these validation object is a pair consisting of the validation 
*          descriptor string and an optional Error message. 
*/ 

function validateForm(objFrm,arrObjDesc) 
{ 
for(var itrobj=0; itrobj < arrObjDesc.length; itrobj++) 
{ 
  if(objFrm.elements.length <= itrobj) 
  { 
       alert("BUG: Obj descriptor for a non existent form element"); 
       return false; 
  }//if 
  for(var itrdesc=0; itrdesc < arrObjDesc[itrobj].length ;itrdesc++) 
  { 
     if(validateData(arrObjDesc[itrobj][itrdesc][0], 
                objFrm[itrobj],arrObjDesc[itrobj][itrdesc][1]) == false) 
      { 
        objFrm[itrobj].focus();
		if (!objFrm[itrobj].selectedIndex) {
		objFrm[itrobj].select()
		}
		
        return false; 
      }//if 
  }//for 
}//for 
}