function check_contactus()
{

	if (emptyField(document.getElementById("ctl00_ContentPlaceHolder1_txtfname")))
	{
		alert("Enter your First Name");
		document.getElementById("ctl00_ContentPlaceHolder1_txtfname").focus();
		return false;
	}
	if (emptyField(document.getElementById("ctl00_ContentPlaceHolder1_txtlname")))
	{
		alert("Enter your Last Name");
		document.getElementById("ctl00_ContentPlaceHolder1_txtlname").focus();
		return false;
	}
	if (emptyField(document.getElementById("ctl00_ContentPlaceHolder1_txtcontact")))
	{
		alert("Enter your Telephone Number");
		document.getElementById("ctl00_ContentPlaceHolder1_txtcontact").focus();
		return false;
	}
	if (emptyField(document.getElementById("ctl00_ContentPlaceHolder1_txtEmail")))
	{
		alert("Enter your e-mail address");
		document.getElementById("ctl00_ContentPlaceHolder1_txtEmail").focus();
		return false;
	}
	arg=document.getElementById("ctl00_ContentPlaceHolder1_txtEmail").value;
	flag=check_email(arg);
	if (flag==0)
	{
		alert('Enter valid e-mail address.');
		document.getElementById("ctl00_ContentPlaceHolder1_txtEmail").focus();
		return false;	
	}
}