try the following line
sqlAgnt = ("Select agentid from Agents where Agents.Agent = '" & cboagent.list(cboagent.listindex) & "'". I'm not sure if this is what you are looking for without knowing a few more specifics about your progam but I bewlive this syntax is correct. Also if it makes sense, when you populate the combo box there is an "ItemData" property that may be usefull to you. Look it up in help.
Rob