I am having a hard time passing variables into functions. It works fine if I pass an integer but when I try and pass a variable it gives me an error. What am I doing wrong? When function newstimer(cur) tries to pass cur into the function change(cur) it "cur is undefined."

function newstimer(cur)
	{
	cur+=1;
	var t=setTimeout("change(cur);",2000);
	}
function change(cur)
	{
document.getElementById('mainNews').style.backgroundImage="url("+mainIMG[cur]+")";
document.getElementById('mainTitle').innerHTML = bigTitle[cur];
document.getElementById('mainTitleSmall').innerHTML = smallTitle[cur];
clearTimeout(t);
newstimer(cur);
	}

You're passing setTimeout a string. This is correct, but it means you'll need to tinker.
I suggest changing

var t=setTimeout("change(cur);",2000);

to

var t=setTimeout("change("+cur+");",2000);

This means you'll pass the value of curr rather than the literal string 'curr'.

Hope this helps,
Tom

That worked perfectly thanks for the help. I had assumed that because it was in the bracket without any quotes just for itself that it wouldnt be a problem but obviously it was