Multiple drop down menu help

[krose]

here's the problem. I have a multiple drop down menu which will show the selections in a text box. However, when a user selects a choice from menu B, menu A's selection disappears from the text box.
My question: how do I save the first selection and build the text so that it contains both the first and second selections.

These is the functions that I have:

function showSelection(cor1)
{
	var w = document.myForm.course6.selectedIndex;
	var selected_text = document.myForm.course6.options[w].text;
	document.getElementById("comments").innerText = "Steve,\n\tYour class schedule for next semester is:\n" + "\nCourse:  "+ selected_text
}

function showSem(sem1)
{
	var w = document.myForm.semester6.selectedIndex;
	var selected_text = document.myForm.semester6.options[w].text;
	document.getElementById("comments").innerText = "Steve,\n\tYour class schedule for next semester is:\n" + "\n\nSemester:  "+ selected_text
}