filling a textbox when dropdown selected item change

Question

Hi

 

I have a Master Table for Lead_Stage

 

Agreement

Closed

Lost

 

Now I want fill the value i.e when i select the item in dropdown 

Agrrement= 70%(should be displayed in the textbox)

Closed=100%

Lost=0%

Followup=0%

 

in the textbox

 

 

plz guide me