Scan bar code and display in textbox and fire click event (onclick) automatically

Hi Frnds,
I have a textbox and a button. onclick of the button, a jquery function is called taking the value of textbox.
But this should done using scanner. User scan the barcode, that code should be displayed in the textbox, as soon as the code get display in the textbox and event should get trigger.
Please tell me how to do this.
Thanks,
Raj4MS