var snippet = new Array();

//Add to the following section for additional random snippets.
snippet[0] = '<img src="/images/studentReading.jpg" alt="" />';
snippet[1] = '<img src="/images/tesla.jpg" alt="" />';
snippet[2] = '<img src="/images/hiblerTeaching.gif" alt="" />';

randomNumber = Math.floor(Math.random() * snippet.length);

document.write(snippet[randomNumber]);