var img=1;
function changeImage(){

if(img==3)
	img=1;
else
	img++;

document.getElementById('index_image').src='slices/index_image_'+img+'.jpg';

setTimeout(changeImage, 10000);

}


//validation function for registration form
function validateContact(email){
	if(!validate())
		return false
	if(!validateEmailAddress(email))
		return false
	return true;
}


//check that all fields with classname 'required' are filled in
function validate(){
var elems=document.getElementsByTagName('input'); 
for(var i=0;i<elems.length;i++){
	if((elems[i].className=='required')&&(elems[i].value=="")){
		alert("Please fill in all required fields");
		return false;
	}
}
return true;
}


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

function enlargeImage(img){
window.open(img, "image", "toolbar=0, scrollbars=0, location=0, statusbar=0, menubar=0, resizeable=0");
}