How can I make a drop down list mandatory?

[Pentium-ant]

This isn’t really website based as such, I work in for a large outbound contact centre and our dialling system displays a script onto our agent’s computers. The script is HTML based and works exactly the same as a website. The problem we have is as the agent goes through the call with our customers they have to capture certain information, they select this information by selecting the most relevant info from a drop down menu. The problem we have is if they forget to select an option from the menus then our reports are not much use to us that we pull from the dialler. Is there any way in html to make sure that when the agent tries to end the call by using the buttons on the script that it will pop up with a box and not allow them to continue without first filling in all the fields?

[mairving]

Several ways to do it but it depends on what programming language that is being used. I usually will build a valid function in php but you can also use javascript validation.