how to control working in combobox_TextChanged() event?

[shaz jazz]

i am using a combobox and a textbox control. text box behaviour depends upon selected value of combobox. These properties of combo box are assingned. AutoComplete = true; AutoCompleteMode = SuggestAppend; AutoCompleteSource = CustomSource AutoDropDown = true; Further more .net 2.0 is under usage with visual Studios 2005. in combobox_TextChanged() event i have assigned some value to textbox control. now i want that when user is typing over the combo box then as he types first letter the TextChanged() event is triggered and my textbox values changes accordingly. i want to control it some how so that when user ends typing only then my textbox values are changed. I tried to control it through combobox.selectionStart and combobox.selectionLength properties but thay always give 0 values. So how should achieve my goal?? Furthermore when user start typing over combobox and in case selection changes then no key event is trigered (i.e keyPress(), keyUp() or keyDown() events)but it selection doesn't changes only then keyUP() event is trigered. Moreover event of combobox_SelectionChangeCommitted()is also tested and it is not triggered when user types on combobox. Any suggestions?

May God help u solv ur problems as well,thx in advance!!