retriving item from sql to textbox2 while typing in textbox1

Question

Dear sir this is the 1st time i am using forum and i need the code and procedure how to retriving itemname from sql to textbox2 while typing itemno. in textbox1

moreinfo: i am preparing billing system in that when we type product id we will be getting list of products as we go on typing in textbox1 and also its price and and discounts in textbox3 and 4 respectively.


Thanks in advance and help me guys m stuck here from past 4days