GetListString:
-------------------------------------------------------------------------------
Get an element from a list uicontrol. Returns empty if there is no string
or the value of the uicontrol is 0.
-------------------------------------------------------------------------------
Form:
s = GetListString( h )
-------------------------------------------------------------------------------
------
Inputs
------
h (1,1) Handle to the string
-------
Outputs
-------
s (1,:) String
-------------------------------------------------------------------------------
Children:
Common: General/DeBlankLT