function sm_CheckEmailFormat(fieldValue)
       { //reference to email field passed as argument

       // Begin Valid Email Address Tests

       //if field is not empty
       if(fieldValue != ''){
               var atSymbol = 0

               //loop through field value string
               for(var a = 0; a < fieldValue.length; a++){

                       //look for @ symbol and for each @ found, increment atSymbol variable by 1
                       if(fieldValue.charAt(a) == '@'){
                               atSymbol++
                       }

               }

               // if more than 1 @ symbol exists
               if(atSymbol > 1){
                       // then cancel and dont submit form
                       return false
               }

               // if 1 @ symbol was found, and it is not the 1st character in string
               if(atSymbol == 1 && fieldValue.charAt(0) != '@'){
                       //look for period at 2nd character after @ symbol
                       var period = fieldValue.indexOf('.',fieldValue.indexOf('@')+2)

                       // '.' immediately following 1st '.' ?
                       var twoPeriods = (fieldValue.charAt((period+1)) == '.') ? true : false

                       //if period was not found OR 2 periods together OR field contains less than 5 characters OR period is in last position
                       if(period == -1 || twoPeriods || fieldValue.length < period + 2 || fieldValue.charAt(fieldValue.length-1)=='.'){
                               // then cancel and dont submit form
                               return false
                       }
               }

               // no @ symbol exists or it is in position 0 (the first character of the field)
               else{
                       // then cancel and dont submit form
                       return false
               }
       }
       // if field is empty
       else{
               // then cancel and dont submit form
               return false
       }

       //all tests passed, submit form
       return true
       }
function sm_validateform(){
	var emailID=document.frmSample.sm_email
	if ((emailID.value==null)||(emailID.value=='')){
		alert('Please check your email address.')
		emailID.focus()
		return false
	}
	if (sm_CheckEmailFormat(emailID.value)==false){
		alert('Please check your email address.')
		emailID.value=''
		emailID.focus()
		return false
	}
	return true
 }