Macro to clear field selections with condition based on variable

[#1]

I want a macro to launch when a user selects a certain value for a variable in an input box.

If the value of the variable varselect_mach= "Time Utilization"

certain fields should be cleared.

I am a real macro beginner, so I don't know if what I am asking is possible.

What I have up to now is:

sub clear_timefields
p = ActiveDocument.Variables("varselect_mach")
if p.GetContent.String = "Time Utilization"
then
set lb = ActiveDocument.GetSheetObject("LB01")
lb.Clear

end sub

but this probably contains syntax errors...