Hola
A ver si esto te da alguna idea
Código Javascript
:
Ver original<html>
<head>
<script type="text/javascript">
function redimensionar (accion) {
var height, width
var alto = document.getElementById("mesa").height;
var ancho = document.getElementById("mesa").width;
if (accion == 'sumar') {
height = parseInt(alto+10);
width = parseInt(ancho+10);
document.getElementById("mesa").style.height = height + "px";
document.getElementById("mesa").style.width = width + "px";
}
else
{
height = parseInt(alto-10);
width = parseInt(ancho-10);
document.getElementById("mesa").style.height = height + "px";
document.getElementById("mesa").style.width = width + "px";
}
}
</script>
</head>
<body>
<img src="iconos/anixmas11.gif" id="mesa" width="50px" height="53px" /><br/>
<input type="button" value="+" onclick="redimensionar('sumar')" /><br/>
<input type="button" value="-" onclick="redimensionar()" />
</body>
</html>
Suerte