Visual Toolchest messages
How to ignore/filter characters while typing field text
Using the VT message VTM_Char (defined in vtcomm.apl) you are able to trap which character is typed into a field (datafield, multiline etc).
When returning FALSE on this message the input is filtered (ignored) on the field.
This way you can filter out certain characters while the user enters text, for instance filter numbers or other characters like @#$% etc etc.
Data Field: dfField Message Actions On VTM_Char ! Filter out SPACE If wParam = 32 Return FALSE
Here you can download a sample: