function emailCheck (email) {
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=email.match(emailPat)
if (matchArray==null) {
alert("email address seems incorrect (check @ and .'s)")
return false
}
var user=matchArray[1]
var domain=matchArray[2]
if (user.match(userPat)==null) {
alert("The username doesn't seem to be valid.")
return false
}
var IPArray=domain.match(ipDomainPat)
if (IPArray!=null) {
// this is an IP address
for (var i=1;i<=4;i++) {
if (IPArray[i]>255) {
alert("Destination IP address is invalid!")
return false
}
}
return true
}
var domainArray=domain.match(domainPat)
if (domainArray==null) 
{
alert("The domain name doesn't seem to be valid.")
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>3) {
alert("The address must end in a three-letter domain, or two letter country.")
return false
}
if (len<2) {
var errStr="This address is missing a hostname!"
alert(errStr)
return false
}
return true;
}

function is_numeric(str)
	{
		if(!str.match(/^[0-9]+$/))
			return false;
		return true;
	}
function validate(frm)
{
if(frm.name.value.length==0)
	{
	alert("Please Fill the Name");
	frm.name.focus();
	return false;
	}
	if(frm.email.value.length==0)
	{
	alert("Please Fill the Email Address");
	frm.email.focus();
	return false;
	}
	if(!emailCheck(frm.email.value))
{
frm.email.focus();
return false;
}
	if(frm.mobile.value.length==0)
	{
	alert("Please Fill the Mobile Number");
	frm.mobile.focus();
	return false;
	}
	if(!is_numeric(frm.mobile.value))
{
alert("Invalid Mobile Number");
frm.mobile.focus();
return false;
}
	
	if(frm.writetous.value.length==0)
	{
	alert("Please Fill the Message");
	frm.writetous.focus();
	return false;
	}
}