Doing this is pretty easy, if you know how or what method to use. I wanted to disable a Validator for a province TextBox if the country DropDownList chosen is USA because the state DropDownList will be enabled so the province should be inactive. Doing this server-side may be easy, but I wanted to use client-side Javascript so that no request will be sent whenever the OnChange event of the country’s DropDownList gets fired. Luckily, there is already a pre-made function in Javascript that disables Validators.

Just set the second parameter as either true or false to enable and disable a Validator. I hope this will help those who have no clue how to go about it like I did until I found out about this function.