function isEmail(elm) {
    if (elm.value.indexOf("@") == "-1" || elm.value.indexOf(".") == "-1" || elm.value == "")
    return true;
    else return false;
}

function checkData_contactform() {

if (document.contactform.name.value.length == 0) {
		alert("Please enter your full name. ");
		document.contactform.name.focus();
       return false;
	};
	
	if (isEmail(document.contactform.email) == true) {
       alert("Please enter a valid Email address.");
		document.contactform.email.focus();
       return false;
    };
	
	if (document.contactform.landline.value.length == 0) {
		alert("Please enter your landline number. ");
		document.contactform.landline.focus();
       return false;
	};
	
	if (document.contactform.mobile.value.length == 0) {
		alert("Please enter your mobile number. ");
		document.contactform.mobile.focus();
       return false;
	};
	
	if (document.contactform.address.value.length == 0) {
		alert("Please enter your address. ");
		document.contactform.address.focus();
       return false;
	};
	
	if (document.contactform.suburb.value.length == 0) {
		alert("Please enter your suburb. ");
		document.contactform.suburb.focus();
       return false;
	};
	
	if (document.contactform.postcode.value.length == 0) {
		alert("Please enter your postal code. ");
		document.contactform.postcode.focus();
       return false;
	};
	
	if (document.contactform.fencetype.selectedIndex == 0) {
		alert("Please select one of the options for - What type of fencing or balustrade is required? ");
		document.contactform.fencetype.focus();
       return false;
	};
	
	if (document.contactform.metres.selectedIndex == 0) {
		alert("Please select one of the options for - How many metres of fencing are required? ");
		document.contactform.metres.focus();
       return false;
	};
	
	if (document.contactform.timeframe.selectedIndex == 0) {
		alert("Please select one of the options for - How soon do you need your fence? ");
		document.contactform.timeframe.focus();
       return false;
	};
	
	return true;
}