function validRequired(formField,fieldLabel,alertmsg)
{
var result = true;
if (formField.value == "")
{
if (alertmsg == "") {
alert('Please enter your ' + fieldLabel +'.');
} else {
alert(alertmsg);
}
formField.focus();
result = false;
}
return result;
}

function echeck(str) {
var at="@"
var dot="."
var lat=str.indexOf(at)
var lstr=str.length
var ldot=str.indexOf(dot)
if (str.indexOf(at)==-1){
alert("Please enter in a valid email address.")
return false
}
if (str.indexOf(at)==-1 || str.indexOf(at)==0 || str.indexOf(at)==lstr){
alert("Please enter in a valid email address.")
return false
}
if (str.indexOf(dot)==-1 || str.indexOf(dot)==0 || str.indexOf(dot)==lstr){
alert("Please enter in a valid email address.")
return false
}
if (str.indexOf(at,(lat+1))!=-1){
alert("Please enter in a valid email address.")
return false
}
if (str.substring(lat-1,lat)==dot || str.substring(lat+1,lat+2)==dot){
alert("Please enter in a valid email address.")
return false
}
if (str.indexOf(dot,(lat+2))==-1){
alert("Please enter in a valid email address.")
return false
}
if (str.indexOf(" ")!=-1){
alert("Please enter in a valid email address.")
return false
}
return true
}


function validate() {

    if (!validRequired(document.contactform.first_name,"first name","")) {
    return false;
    }
	
	if (!validRequired(document.contactform.last_name,"last name","")) {
    return false;
    }
	
	if (!validRequired(document.contactform.email,"email","")) {
    return false;
    }
	
	if (!echeck(document.contactform.email.value)) {
	document.contactform.email.focus();
	return false;
	}
    
	if (!validRequired(document.contactform.comments,"comment","")) {
    return false;
    }

	return true;
}