median js

[keyboard]

I'm doing all the basic average functions (Maths)

function median(elem,returnType) {
	if(typeof returnType == "undefined") {
		var returnType = "1";
	}
    elem.sort(sortMethod);
	var numType;
	var half1 = elem.length / 2;
	var half2;	
	var halfminused;
	var halfdivided;
	var plus1;
	var median;
	if(elem.length % 2) {
		plus1 = Math.floor(half1); //As i[1] is actually the second value in an array not the first, we've got to floor() it instead of ceil();
		median = elem[plus1];
	} else {
		half2 = half1 + 1;
		halfminused = half2 - half1;
		halfdivided = halfminused / 2;
		median = half1 + halfdivided;	
	}
	if(returnType == "1") {
		return {median : median};
	} else {
		if(returnType == "2") {
			return median;
		}
	}
	return median;
}

Is there a simpler way to do this???

[keyboard]

Hmmm, another question to add on to that -

How would you find the most common value in an array (not jQuery):

var array1=new Array();
 array1[0]="1"; 
 array1[1]="4";
 array1[2]="4";
 array1[3]="4";
 array1[4]="5";
 array1[5]="5";
 array1[6]="7";

Run it through a function and it should output 4 (maths - averages - mode).

Any help???