List component. Help. Looked everywhere. Button and list

1

Trying to use a list component and a button. When user selects something from list component and clicks button it takes them to new page, if user doesnt select something from list and hits button, (this is where my question lies) I want it to do nothing and setFocus to list component.

Here is how I am going about it now: New if statement (however it still transfers user if nothing is selected from list component) How can I get it to not transfer? I have tried rewritting this many ways, searched all over the nets, and Nada.


var arUrl:Array=["/browsecategory.aspx?cat=1","/browsecategory.aspx?cat=2","/browsecategory.aspx?cat=3","/browsecategory.aspx?cat=4"];

var provider:Array=[{label:"Option 1",data:0},{label:"Option 2",data:1},{label:"Option 3",data:2},{label:"Option 4",data:3} ];

mcList.dataProvider=provider;
var obj:Object={};
obj.click=function(eo:Object)
{
var count:Number=mcList.selectedItem.data;
getURL(arUrl[count],"_blank");
trace("count="+arUrl[count]);
}
but.mcSubmit.addEventListener("click",obj);/////here is where I am sending off
if(mcList.selectedIndex == undefined) {
setFocus.mcList;
}

So this thing works perfectly, however if user hasnt selected anything how can I get it to not transfer and setFocus?

I have tried setting if to check it for - 1 (since starts at 0) set to 0? Any ideas please help. Thanks in advance MT