Hi i have 2 radio buttons,

i) default value
ii) specify value

and 3 textboxes
i)width
ii)height
iii)size

the 3 texboxes are placed within a frame

Now if the user chooses default value, i wan to gray out the 3 texboxes and disable them. However, when the user selects specify value, onli then will i enable the 3 textboxes. It can be done using IF THEN statements, however, which SUB should i place my statements in?