// Assign the last modified date to the variable lastmoddate
var lastmoddate = document.lastModified;

// Create an if statement to test the value of lastmoddate
if(lastmoddate == 0) {
     var pageData = "© 2006 Copyright James M. Tuck III. \nLast Modified: Unknown" ;
}
else {
     var pageData = "© 2006 Copyright James M. Tuck III. \nLast Modified: " + lastmoddate ;
}