>You may try using the TRY / CATCH.
>
>

>var oH = 0;
>try {
>     if (LevelExteremaListHeight)
>     {
>         oH = LevelExteremaListHeight
>     }
>CATCH {
>     oH = <somedefault value or don't change>
>}
>

>
>I thought there was a function similar to VARTYPE, but I may be thinking of VBscript.
>
>I use too many languages.

Thanks

I had to adjust to:

     if (window.LevelExtremeListHeight)
     {
         oH = window.LevelExtremeListHeight
     }

to make it work.