function setMainImage(url){
	document.getElementById('main_image').src=url;
}

//validation function for registration form
function validateForm1(){
	if(!validate("form1"))
		return false
	if(!validateEmailAddress('form1'))
		return false
	return true;
}
function validateForm2(){
	if(!validate("form2"))
		return false
	if(!validateEmailAddress('form2'))
		return false
	return true;
}
//check that all fields with classname 'required' are filled in
function validate(f){
var elems=f.elements; 
valid=true;
for(var i=0;i<elems.length;i++){
	if(elems[i].className=='required'){
		switch(elems[i].type) {
			case "text" :
			case "password" :
				if(elems[i].value==""){
					valid=false;
					alert("Please fill in all required fields");
				}
				break;
			case "radio" :
				valid = isSelected(f.name, elems[i].name);
				break;
		}
		if(!valid){
			return valid;
		}
	}
}
return true;
}

/** isChecked
 * returns true if at least one of a group of checkboxes is checked
 **/
function isChecked(formname, checkboxname){
	var isChecked = false;
	var chkbx=eval('document.'+formname+'.'+checkboxname);
	for (var i = 0; i < chkbx.length; i++) {
  	 	if (chkbx[i].checked) {
   	   	isChecked = true;
   		}
	}
	if(!isChecked)
		alert("Please tick all required checkboxes");
	return isChecked;
}

/** isSelected()
 * Returns true if one of a group of radio buttons is selected
 **/
function isSelected(formname, radioname){
	var isChecked = false;
	var arr = radioname.split("[");
	var chkbx=eval('document.'+formname+'.'+arr[0]);
	if(!chkbx.length){
		if(chkbx.checked)
			isChecked=true;
	}
	else{
		for (var i = 0; i < chkbx.length; i++) {
			if (chkbx[i].checked) {
			isChecked = true;
			}
		}
	}
	if(!isChecked)
		alert("Please tick all required Radio buttons");
	return isChecked;
}

/*** This validation function checks that an email address contains both '@' and '.' **/
function validateEmailAddress(formname){
var email = eval('document.'+formname+'.'+email_address.value);
	if((email.indexOf('@')==-1)||(email.indexOf('.')==-1)){
		alert("Invalid email address");
		return false;
	}
	else
		return true;
}

//Check that two fields have the same values, useful for password changes etc
function validateSame(type, retype){
if(document.getElementById(type).value == document.getElementById(retype).value)
	return true;
else{
	return false;
}
}



/**************** AJAX STUFF **************/


/*** load up newsfeeds ***/

function loadNewsfeed(feed){

	var url='ajax/loadNewsfeed.php?feed='+feed;
		AjaxRequest.get(
			{
			  'url': url
			  ,'onSuccess':function(req){
				results = req.responseText;
				document.getElementById('newsfeed_content').innerHTML = results;
		 }
			}
		  );
}