Removing duplicate values from the Combo box

ELPASOUser2_(Delete)_2549571

We are customizing livelink for our company needs.We are connecting to an external datbase using CAPI and populating the combo box.In combo box we are getting duplicate values.Can anybody suggest us how to eliminate the duplicates?..We feel it can be done by using javascript..if anybody has the sample,please let us know.PS:SQL queries with "UNIQUE" in the statement is not preffered.