function ShowPic (whichpic, whichtit) {
// update big picture with the right picture.
// update its title with the right title
document.showcaseimg.src = whichpic;
document.showcaseimg.alt = whichtit;
// showcasetit is the title to display
var showcasetit = whichtit;
// point to the right paragraph
var para = document.getElementById("thistit");
// get rid of old text
for (i=0;i<para.childNodes.length;i++){
para.removeChild(para.childNodes[i]);
}
// set the style for the new paragraph
para.style.fontFamily = "Geneva, Verdana,  Arial, Helvetica, sans-serif";
para.style.fontSize = 13;
para.style.fontWeight="normal";
para.style.textAlign = "center";
para.style.fontColor="#708090";

// put the text in a node
var newText = document.createTextNode(showcasetit);
// put the node in the right paragraph
para.appendChild(newText);
}