function clearDefault(el) {
if (el.defaultValue==el.value) el.value = ""
}
<!--
var name = 'blank';
var homepage = null;
var picture = null;
var descriptive = null;
var overswitch = null
if (document.images) {
	  img1on = new Image();
      img1on.src = "./img/mnu/hak2.gif";
	  img2on = new Image();
      img2on.src = "./img/mnu/faal2.gif";
	  img3on = new Image();
      img3on.src = "./img/mnu/ref2.gif";
	  img4on = new Image();
      img4on.src = "./img/mnu/ik2.gif";
	  img5on = new Image();
      img5on.src = "./img/mnu/iletisim2.gif";	  	  
		  	  	    
 	  img1off = new Image();
      img1off.src = "./img/mnu/hak1.gif";
	  img2off = new Image();
      img2off.src = "./img/mnu/faal1.gif";
	  img3off = new Image();
      img3off.src = "./img/mnu/ref1.gif";
	  img4off = new Image();
      img4off.src = "./img/mnu/ik1.gif";
	  img5off = new Image();
      img5off.src = "./img/mnu/iletisim1.gif";  
  }
function imgOn(imgName) {
        if (document.images) {
            document[imgName].src = eval(imgName + "on.src");
        }
}
function imgOff(imgName) {
        if (document.images) {
            document[imgName].src = eval(imgName + "off.src");
        }
}
// -->