Thanks to all of you,
actually i have downloaded "valitText .dll" but the problem is that user cant reach to the decimal point by pressing "." and while data-entry user cant use arrow keys or any other keys except numeric keys . so it is useless in dataentry type application. and if i have to do some excercise in text changed event, then what is the use of "validText.dll" . i m still using .net 2002, . is there ready to use control which will facilitate all this needs in 2003 or newer version .