Thread: change value of text box

below is function currently i m calling on oblur event of my text box.but what i needed as soon as user input value in textbox immdly that value should added or subtracted from another text box.should not wait for focus lost.

Code:

function mCalculateSumInvoice(LineNumber)						{
						 
							document.getElementById("txtInvoicedQuantity"+LineNumber).value =  parseInt(document.getElementById("txtInvoicedQuantity"+LineNumber).value) +   parseInt(document.getElementById("txtAdjustmentToAcceptedQuantity"+LineNumber).value);
						}