function validate_contactus(){
	if (document.contactus_form.txtName.value == ""){
    	alert("Please enter your Full Name.");
		//contactus_form.txtName.focus();
		return false;
	} else if (document.contactus_form.txtPhone.value == ""){
    	alert("Please enter your Contact Number.");
		//contactus_form.txtPhone.focus();
		return false;
	} else if (document.contactus_form.txtMessage.value == ""){
    	alert("Please enter your Message.");
		return false;
	} else if (document.contactus_form.security_code.value == ""){
    	alert("Please enter Security Codes.");
		//contactus_form.security_code.focus();
		return false;
	} else if (document.contactus_form.txtEmail.value != ""){
		return checkmail(document.contactus_form.txtEmail);
	} else{
		return true;
	}
}

var emailfilter=/^\w+[\+\.\w-]*@([\w-]+\.)*\w+[\w-]*\.([a-z]{2,4}|\d+)$/i;
function checkmail(e){
	var returnval=emailfilter.test(e.value);
		if (returnval==false){
			alert("Please enter a valid Email Address.");
			e.select();
		}
	return returnval;
}