//validates user's search options
function force_pick (form) {
	var loc = false; //boolean that holds whether or not user has picked a location
	var cat = false; //boolean that holds whether or not the user has picked a category
	var s_loc = "Please Select one or more Locations.";
	var s_cat = "Please Select one or more Categories.";
	for (i = 0; i<document.getElementById("cat_size").value; i++)//for every option in the listbox
	{
		if (document.getElementById("cat_list")[i].selected == true)//if the option is selected
		{
			cat = true;	//at least one category is selected at this point
		}
	}
	for (i = 0; i<document.getElementById("loc_size").value; i++)//for every location checkbox
	{
		if (document.getElementById("loc_list")[i].selected == true)//if this check box is checked
		{
			loc = true;	//at least one location has been selected
		}
	}
	if (!loc && !cat)//neither locations nor categories
	{
		alert(s_loc + "\n" + s_cat);
		return false;
	}
	else if (!loc && cat)//no locations
	{
		alert(s_loc);
		return false;
	}
	else if (loc && !cat)//no categories
	{
		alert(s_cat);
		return false;
	}
	else if (loc && cat)//good to go (at least one option from each data set has been chosen)
	{
		return true;
		form.submit();
	}
}
function select_all()
{
	var list = document.getElementById("cat_list");
	for(var i=0;i<list.options.length;i++)
	{
		list.options[i].selected=true;
	}
}