Ajax Auto complete based on web service

Question

Hi All,

I have a drop down and two auto complete text boxes in may aspx page

first auto complete text box should be based on first drop down that is working fine

but 

second auto complete text box should be based on  first auto complete text box web method gets the first auto complete text box as empty but I need to  pass the first auto complete text box value also. kindly please give me idea on this logic