function validateForm(form)
{
	var userName = trim(form.userName.value);
	var userEmail = trim(form.userEmail.value);
	var userEnquiry = trim(form.userEnquiry.value);
	
	if (userName == "") {
		alert("Please enter your name.");
		form.userName.focus();
		return false;
	}
	if (userEmail == "") {
		alert("Please enter your email address.");
		form.userEmail.focus();
		return false;
	}
	if (userEnquiry == "") {
		alert("Please enter your enquiry.");
		form.userEnquiry.focus();
		return false;
	}
	if (!isValidEmail(userEmail)) {
		alert("Please enter a valid email address.");
		form.userEmail.focus();
		return false;
	}
	
	return true;
}

function trim(w)
{
	while (w.length>0 && (w.substr(0,1) == ' ' || w.substr(0,1) =='กก')) {w=w.substr(1)};
    while (w.length>0 && (w.substr(w.length-1)== ' ' || w.substr(w.length-1)=='กก')) {w=w.substr(0,w.length-1);}
        return w;
}

function isValidEmail(emailStr)
{
   if (emailStr.length == 0) {
       return true;
   }
   var emailPat=/^(.+)@(.+)$/;
   var specialChars="\\(\\)<>@,;:\\\\\\\"\\.\\[\\]";
   var validChars="\[^\\s" + specialChars + "\]";
   var quotedUser="(\"[^\"]*\")";
   var ipDomainPat=/^(\d{1,3})[.](\d{1,3})[.](\d{1,3})[.](\d{1,3})$/;
   var atom=validChars + '+';
   var word="(" + atom + "|" + quotedUser + ")";
   var userPat=new RegExp("^" + word + "(\\." + word + ")*$");
   var domainPat=new RegExp("^" + atom + "(\\." + atom + ")*$");
   var matchArray=emailStr.match(emailPat);
   if (matchArray == null) {
       return false;
   }
   var user=matchArray[1];
   var domain=matchArray[2];
   if (user.match(userPat) == null) {
       return false;
   }
   var IPArray = domain.match(ipDomainPat);
   if (IPArray != null) {
       for (var i = 1; i <= 4; i++) {
          if (IPArray[i] > 255) {
             return false;
          }
       }
       return true;
   }
   var domainArray=domain.match(domainPat);
   if (domainArray == null) {
       return false;
   }
   var atomPat=new RegExp(atom,"g");
   var domArr=domain.match(atomPat);
   var len=domArr.length;
   if ((domArr[domArr.length-1].length < 2) ||
       (domArr[domArr.length-1].length > 6)) {
       return false;
   }
   if (len < 2) {
       return false;
   }
   return true;
}