Need to restrict some users for entering value to textbox

Question

I have a textbox in which I need to insert numeric value for a certain range according to user. If the user is "staff", then

he can insert a value range of 0-100 on the textbox and if the user is "admin" he can insert 0-100 in the text box.

I have used range validator, but it only shows error only and the user can type the value. How can I achieve this.