function createCallNumberLinks() {
var allSpans = document.getElementsByTagName('span');

var callNums = new Array();

for (var i = 0; i < allSpans.length; i++)
	if (allSpans[i].className == "call-number") {
		callStr = new String(allSpans[i].innerHTML);
		allSpans[i].innerHTML = '<a href="http://polycat.lib.calpoly.edu/search/c?SEARCH=' + encodeURIComponent(callStr) + '&SUBMIT=Search">' + callStr + '\<\/a>';
	}

return callNums;
}