<!--// Begin for a form called finance
function checkEmail(myForm) {
if (/^\w+([\.-]?\w+)*@\w+([\.-]?\w+)*(\.\w{2,3})+$/.test(finance.Email.value)){
return (true)
}
alert("Invalid E-mail Address! Please re-enter.")
return (false)
}

function checkRequired(frmData) { 
var bFail; 
bFail = false; // Default to pass 

for(iElement = 0; iElement < frmData.elements.length; iElement++) { 

if(frmData.elements[iElement].className == 'RequiredTextBox' || 
frmData.elements[iElement].className == 'FailedTextBox') { 

if(frmData.elements[iElement].value == '') { 
bFail = true; 
frmData.elements[iElement].className = 'FailedTextBox'; 

} else { 

frmData.elements[iElement].className = 'RequiredTextBox'; 

} 

} 

} 

return !bFail; 

} 

function checkForm() { 
if(!checkRequired(document.forms['finance'])) { 

if(document.all) { 
document.all.spanError.innerText = 'Please fill in all fields marked in Red.'; 
} else { 
document.getElementById('spanError').innerHTML = 'Please fill in all required fields.'; 
} 
} else { 

document.forms['finance'].submit(); 

}
} 

// Declaring required variables
var digits = "0123456789";
// non-digit characters which are allowed in phone numbers
var phoneNumberDelimiters = "()- ";
// characters which are allowed in international phone numbers
// (a leading + is OK)
var validWorldPhoneChars = phoneNumberDelimiters + "+";
// Minimum no of digits in an international phone no.
var minDigitsInIPhoneNumber = 10;

function isInteger(s)
{   var i;
    for (i = 0; i < s.length; i++)
    {   
        // Check that current character is number.
        var c = s.charAt(i);
        if (((c < "0") || (c > "9"))) return false;
    }
    // All characters are numbers.
    return true;
}

function stripCharsInBag(s, bag)
{   var i;
    var returnString = "";
    // Search through string's characters one by one.
    // If character is not in bag, append to returnString.
    for (i = 0; i < s.length; i++)
    {   
        // Check that current character isn't whitespace.
        var c = s.charAt(i);
        if (bag.indexOf(c) == -1) returnString += c;
    }
    return returnString;
}

function checkInternationalPhone(strPhone){
s=stripCharsInBag(strPhone,validWorldPhoneChars);
return (isInteger(s) && s.length >= minDigitsInIPhoneNumber);
}

function ValidateForm(tele){
	var Phone=tele	

	if (checkInternationalPhone(tele)==false){
		alert("Please Enter a Valid Phone Number")
		//tele.focus()
		return false
	}
	return true
 }

function check_date(field){
var checkstr = "0123456789";
var DateField = field;
var Datevalue = "";
var DateTemp = "";
var seperator = "-";
var day;
var month;
var year;
var leap = 0;
var err = 0;
var i;
   err = 0;
   DateValue = DateField.value;
   /* Delete all chars except 0..9 */
   for (i = 0; i < DateValue.length; i++) {
	  if (checkstr.indexOf(DateValue.substr(i,1)) >= 0) {
	     DateTemp = DateTemp + DateValue.substr(i,1);
	  }
   }
   DateValue = DateTemp;
   /* Always change date to 8 digits - string*/
   /* if year is entered as 2-digit / always assume 20xx */
   if (DateValue.length == 6) {
      DateValue = DateValue.substr(0,4) + '20' + DateValue.substr(4,2); }
   if (DateValue.length != 8) {
      err = 19;}
   /* year is wrong if year = 0000 */
   year = DateValue.substr(4,4);
   if (year == 0) {
      err = 20;
   }
   /* Validation of month*/
   month = DateValue.substr(2,2);
   if ((month < 1) || (month > 12)) {
      err = 21;
   }
   /* Validation of day*/
   day = DateValue.substr(0,2);
   if (day < 1) {
     err = 22;
   }
   /* Validation leap-year / february / day */
   if ((year % 4 == 0) || (year % 100 == 0) || (year % 400 == 0)) {
      leap = 1;
   }
   if ((month == 2) && (leap == 1) && (day > 29)) {
      err = 23;
   }
   if ((month == 2) && (leap != 1) && (day > 28)) {
      err = 24;
   }
   /* Validation of other months */
   if ((day > 31) && ((month == "01") || (month == "03") || (month == "05") || (month == "07") || (month == "08") || (month == "10") || (month == "12"))) {
      err = 25;
   }
   if ((day > 30) && ((month == "04") || (month == "06") || (month == "09") || (month == "11"))) {
      err = 26;
   }
   /* if 00 ist entered, no error, deleting the entry */
   if ((day == 0) && (month == 0) && (year == 00)) {
      err = 0; day = ""; month = ""; year = ""; seperator = "";
   }
   /* if no error, write the completed date to Input-Field (e.g. 13.12.2001) */
   if (err == 0) {
      DateField.value = day + seperator + month + seperator + year;
   }
   /* Error-message if err != 0 */
   else {
      alert("Date is incorrect!");
      DateField.select();
	  DateField.focus();
   }
}
<!--//  End -->