How to set dropdown input value base on another dropdown list select value

[stggst]

i have 2 drop down list (form control combo box) 1st one contains A,B,C i want to set 2nd one selected list based on 1st one selected value.that means if i select A in 1st one i want to set D,E,F in 2nd one and if i Select B in 1st one and i want to set 2nd list G,H,I.how can i do this .please assist me to do this

 

[AliGW]

Have a look here: http://www.contextures.com/xlDataVal02.html