Set Numeric Input

This is one trick to set up our form variable into numeric.

The fscommand2 is SetInputTextType, and it works on 6620.

You have to be sure that "variableName" matches the variable that you've
assigned to the text field, e.g. if your text field property has the
"Var:" property set to input1, you should use

fscommand2("SetInputTextType", "input1", "Numeric");