How to do a variable menu in CCP4i Tcl:

First, add a typedef for the new varmenu we are about to create:

   set typedef(_input_columns) { varmenu INPUT_COLUMNS_LIST INPUT_COLUMNS_ALIAS 8 }

Then, add code to the place where you want to change the varmenu (for example, a subroutine like "add_an_input_column".

   UpdateVariableMenu $arrayname initialise [llength $array(INPUT_COLUMNS_LIST,0)]           INPUT_COLUMNS_LIST $columns           INPUT_COLUMNS_ALIAS $columns

Then add code for INPUT_COLUMNS to your .def file:

INPUT_COLUMNS,0                _input_columns      ""
INPUT_COLUMNS_LIST,0           _list_of_text       {"test1" "test2" }
INPUT_COLUMNS_ALIAS,0          _list_of_text       {"TESTT1" "TESTT2" }

Finally, create the widget as you would do so normally:

                                                                     
    CreateLine line         label "Input columns"         widget INPUT_COLUMNS