Use JavaScript Function on blur() and on focus() in ASP.NET

Step 1
 
Just drag one simple textbox from toolbox and just add attributes like the below screen shot.
 
 
Step 2
 
Then as we know, just write the required functions inside the Script tag like below:
 
 
That's it, now this function will be triggered inthe  client side and you will get the Output like the below screen shot
 
Output 1
 
While Cursor is on the Bill no,
 
 
Note
 
Changed to the Yellow Color since we have provided the color as "Yellow" in the myFocusFuction() in the above JavaScript code.
 
Output 2
 
Once it came out of the Bill No.
 
 
Note
 
Back to the Normal Color since we didn't provide any color in the myBlurFuction() in the above JavaScript code.