<!DOCTYPE html>
<html lang="de">
<head>
<title>Document</title>
<script src="jquery.js" type="text/javascript"></script>
<script type="text/javascript">
$(document).ready(function () {
$("#div1").fadeOut("fast");
$("#div2").fadeOut("fast");
$("#div3").fadeOut("fast");
});
function tuwas() {
if ($("#dropdown").val() == "1") {
$("#div2").fadeOut("fast");
$("#div3").fadeOut("fast");
$("#div1").fadeIn(1500);
} else if ($("#dropdown").val() == "2") {
$("#div1").fadeOut("fast");
$("#div3").fadeOut("fast");
$("#div2").fadeIn(1500);
} else if ($("#dropdown").val() == "3") {
$("#div1").fadeOut("fast");
$("#div2").fadeOut("fast");
$("#div3").fadeIn(1500);
}
}
</script>
<meta charset="UTF-8">
</head>
<body>
<select name="dropdown" id="dropdown" onchange="tuwas()" >
<option value="">Auswahl</option>
<option value="1">div1</option>
<option value="2">div2</option>
<option value="3">div3</option>
</select>
<div id="div1">
<p>Das ist div1.</p>
</div>
<div id="div2">
<p>Das ist div2.</p>
</div>
<div id="div3">
<p>Das ist div3.</p>
</div>
</body>
</html>