Focusing cursor Automatically to next tabbed textbox in asp

Question

HI,

i am using Asp.net, i had four textboxes side by side,. i had given max lenghth of each text box is 3 in asp.net, so that while entering the value in first textbox id i had entered the 4th value it shoul automatically focus to the next textbox , using Asp.net and java script...

can any one help me am a beginer in java script.