POST variables to DSP service

I am trying to pass variables from a multiple selection box to enter the values in a database. I am having a problem trying to input these values into the service because they are all passed with the same variable name. (If the name=“selectedList”, all name=value pairs will have the same name). When I try to input this into a webMethods service, I only get the first value. My only thought so far is to pass the variables using GET and parse the url to extract all of the selectedList items that I wish to view. Do you know of an easier way or how this might be accomplished? Javascript onSubmit()?