HELP!!

Have form elements between two background layers (z-index set to -1 and 0). But when I show a layer above the form elements (triggered from a menu drop down list of dynamically produced data from a database table) they all appear above the layer (N4) and the select drop down shows above in the layer (IE). I have set the z-index to 2 for the above layer. Even tried placing the form into a layer and setting the z-index to 1!!
Would very much appreciate any thoughts...

Regards
Adam