function isEmail(str)// verify email
{
 	if(str.indexOf('@')==-1||str.indexOf('.')==-1)  return false;
  	if(str.length<5)  return false;
 	return true;
}

function regsub()
{
	//form validatation
	if(document.mailingfrm.txtname.value=="")	//name(empty)
  	{
		alert ("Please Fill In Your Name!");
    	document.mailingfrm.txtname.focus();
		document.mailingfrm.txtname.select();
		return false;
  	}
  	if(document.mailingfrm.txtemail.value=="")	//email(empty)
  	{
		alert ("Please Fill In Your Email Addreaa!");
    	document.mailingfrm.txtemail.focus();
		document.mailingfrm.txtemail.select();
		return false;
 	}	
  	if(!isEmail(document.mailingfrm.txtemail.value)) //not email address
  	{
		alert ("Invalid Email Address!");
    	document.mailingfrm.txtemail.focus();
		document.mailingfrm.txtemail.select();
		return false;
  	}		
}