lastmod = new Date(document.lastModified);     // get string of last modified date
lastmoddate = Date.parse(lastmod);             // convert modified string to date
if(lastmoddate == 0){                          // unknown date (or January 1,
																						 // 1970 GMT)

document.writeln("<p class='update'>Unknown</p>");
} else {
document.writeln("Last Update: " + lastmod.format('MM/dd/yyyy'));
}