Ajax combobox problem

I have populated an ajax combobox from an sql datasource. only two rows are there in the combo.

DisplayText 'abc'
Value '1234'

DisplayText 'abc'
Value '9874'

when I display the selected value and text in the selectChaned Event, I get only the first text and value regardless of the selection. what how dispaly the select text and value?

if I change the text 'abc' to 'abc2' in one of them then I get the correct text and value.

how can I fix the problem?

ayha