validate

i have a drop down list with weight range values i.e 1-50 or 51-70 and so forth and i have a textbox that the user enters a value for the weight according to the weight range. i want the user to only enter a value within this range and how do i validate for this

hello, I need some suggestions on this one. Is there any way to validate textboxes?? Like for some, you can only insert numeric characters, for others only alphabetical characters? And I wanna validate em at da keypress event. I know how to do it using coding on ASCII keys. But can anyone give...