multiple list box duplicate value checking

I have a form with multiple list boxes, each containing the same values. However, a value can only be chosen once. Here's the code I'm using to check the exit event of the first listbox:

var juris = new Array(3);
for (x = 0; x < 2; x++){
juris[x] = xfa.resolveNode("jlist["+x+"]").rawValue;
}
for (y in juris){
if (y != 0){
if (this.rawValue == juris[y]){
xfa.host.messageBox(this.formattedValue + " already listed","Information",3,0);
}
}
}

This works well but I have to change the code for each listbox so it doesn't check itself. I do this using the if (y != 0) for list[0] and would change this to if (y != 1) for list[1], etc.

Can anyone tell me how to capture the current lists' index value ([0],[1].etc) within the array so I can assign that value to variable z and use if (y != z) for each list?

Thanks