"has no property error"

[madhwal]

why do we get the "xxx has no property" error,and what could be the resolution.
i get this error in following

"cell has no property"

if (document.layers) {
var cell=eval('parent.frames['+frameNumber+'].document.form_combine_sources["'+ str_tableID +'.'+ str_rowIndex +'.'+ str_cellIndex+'"].document');

cell.visibility = 'hide';

here i have to set the cell of a table as disabled.

[A1ien51]

This is the basic idea:

TheCell=parent.FramName.document.getElementById("Row" + RNum +"Col" + CNum).style;

TheCell.visibility="hidden";