SOURCE

function getMax(arr) {
	var max = arr[0];
	for (var i = 1; i < arr.length; i++) {
		if (max < arr[i]) {
			max = arr[i];
		}
	}
	 document.write( max + "<br/>");
}
var array = [97, 22, 67, 87, 41];
getMax(array);