Hw 2 Disable/Enable Keyboard inputs on Form Load of ASP.net?

Question

Hi Friendz,
 
I am developing a Online Learning Project in ASP.net using C sharp coding, If a user clicks start button i making ppt to run automatically for learning via coding but i want to block the some of the keyboard inputs while learning in online and if the user close the form then all keyboard inputs should work properly, so can any one suggest me , how to block some keyboard inputs in form load. Thanks in Advance .