>>>>Do you know what is wrong in my implementation and what would be the best way to fix it?
>>>>
>>>
>>>Move the code to the textbox Keypress event and use nodefault if space is entered.
>>>
>>>Like
>>>
>>>

>>>IF this.lNoSpacesAllowed and nKeyCode=32
>>>NODEFAULT
>>>ENDIF
>>>

>>
>>Thanks - our thoughts crossed as I just did exactly the same. I added 9 also just in case for TAB.
>
>TAB?
>You can't TAB in the textbox. The TAB is used for moving focus :-)

Exactly - I just realized that and was going to make an update.