popupmenu dosent overlap dropdown list

Use z-index & position property in CSS for Menu Control. Please post your relevant code where you face the trouble/issue.

The z-index property specifies the stack order of an element.

An element with greater stack order is always in front of an element with a lower stack order.

Note: z-index only works on positioned elements (position:absolute, position:relative, or position:fixed)

.mnuMenu
{
position:absolute;
z-index:1;
}