// JavaScript Document to extract arguments from a url (pg. 214)

function roll_sc_nav(sc_arg)
{
	var sc_arg_value = sc_arg; // store sc_arg in a new variable and perform string functions on it
	
	//strip last character off of value passed to sc_arg, this should always be a number
	var last_char = sc_arg_value.substring(sc_arg_value.length - 1);
	
	//take said number, put in on the end of id = sc_nav_
	var sc_arg_nav = "sc_nav_" + last_char;
	
	scn = document.getElementById(sc_arg_nav);
	
	//take the new value of sc_nav_#, and set its classname to over
	if(scn != null)
	{
		scn.className+=" over";
	}
}


/*
this function parses a comma separated name=value argument pairs from 
the query string of the URL. It stores the name=value pairs in
properties of an object and returns that object.
*/

function getArgs()
{
	var args = new Object();
	var query = location.search.substring(1); //get query string
	var pairs = query.split("&"); //break at ampersands
	for(var i=0; i < pairs.length; i++)
	{
		var pos = pairs[i].indexOf('=');  //look for "name=value"
		if(pos == -1) continue;  // if not found, skip
		var argname = pairs[i].substring(0,pos);  // extract the name
		var value = pairs[i].substring(pos+1);  //extract the value
		args[argname] = unescape(value);   //store as a property
	}
	
	//if no product is clicked on, automatically load sub_content_1
	if(args['show'] == undefined)
	{
		args['show'] = "sub_content_1"; 
	}
	
	//call function to determine the corresponding sc_nav element, and set it's classname to over
	roll_sc_nav(args['show']);
	
	//call fcn hideNshow to show passed variable stored in show
	hideNshow(args['show']);
	
}

//add feature to this function to add classname of over to corresponding sc_nav li element