/**
 * DHTML email validation script. Courtesy of SmartWebby.com (http://www.smartwebby.com/dhtml/)
 */

function email_check(str) {

		var at="@";
		var dot=".";
		var lat=str.indexOf(at);
		var lstr=str.length;
		var ldot=str.indexOf(dot);
		if (str.indexOf(at)==-1){
		   return false;
		}

		if (str.indexOf(at)==-1 || str.indexOf(at)==0 || str.indexOf(at)==lstr){
		   return false;
		}

		if (str.indexOf(dot)==-1 || str.indexOf(dot)==0 || str.indexOf(dot)==lstr){
		    return false;
		}

		 if (str.indexOf(at,(lat+1))!=-1){
		    return false;
		 }

		 if (str.substring(lat-1,lat)==dot || str.substring(lat+1,lat+2)==dot){
		    return false;
		 }

		 if (str.indexOf(dot,(lat+2))==-1){
		    return false;
		 }
		
		 if (str.indexOf(" ")!=-1){
		    return false;
		 }

 		 return true;					
	}

function validateSignup() {
	
	var email = document.newsletter.email.value;
	var firstname = document.newsletter.firstname.value;
	var lastname = document.newsletter.lastname.value;
	var org = document.newsletter.organisation.value;
	var phone = document.newsletter.phone.value;
	
	var category_1 = document.newsletter.category_1.checked;
	var category_2 = document.newsletter.category_2.checked;
	var category_3 = document.newsletter.category_3.checked;
	var category_4 = document.newsletter.category_4.checked;
	var category_5 = document.newsletter.category_5.checked;
	var category_6 = document.newsletter.category_6.checked;
	var category_7 = document.newsletter.category_7.checked;

	if ((firstname==null)||(firstname=="")){
		alert("Please enter your first name.");
		return false;
	}	
	
	if ((lastname==null)||(lastname=="")){
		alert("Please enter your last name.");
		return false;
	}		
	
	if ((org==null)||(org=="")){
		alert("Please enter your organisation.");
		return false;
	}		
	
	if ((email==null)||(email=="")){
		alert("Please enter your email address.");
		return false;
	}
	
	if ((phone==null)||(phone=="")){
		alert("Please enter your phone number.");
		return false;
	}			
	
	if (email_check(email)==false){
		alert("Email address is invalid.");
		return false;
	}	

	if ((category_1==false)&&(category_2==false)&&(category_3==false)&&(category_4==false)&&(category_5==false)&&(category_6==false)&&(category_7==false)){
		alert("Please select at least one category of interest.");
		return false;
	}	

	return true;
 }