Timer prob in Textbox

Question

Hai, Good Eve Friends,

 

              I have problem in timer using textbox.  Now i need to put manual entry time

              like this, HH:MM:SS. 24:59:59...I just want to make entry in single textbox. I tried this concept in MaskEditExtender but i have one problem in that 

              minutes and seconds will be make entry above 59. I want to restrict that. suppose i make entry minutes and seconds above 59 means it  won't be                 allow to entry. Please, I don't need validation messages. I need entry restriction above 59.

 

              I need all of your Helps, 

              

              Thank You Friends in Advance,