function formLeeren()
{
  	var form = document.forms["anmeldeform"]; // bezieht sich auf die ID des form tags 
    if (form) {
		for (i = 0; i < form.elements.length; i++) {
			if (form.elements[i].type == 'text' || form.elements[i].type == 'textarea') {
				form.elements[i].onfocus = function(){
					if (this.value == this.defaultValue) {
						this.value = '';
					}
				}
				form.elements[i].onblur = function(){
					if (this.value == '') {
						this.value = this.defaultValue;
					}
				}
			}
		}
	}
}

window.onload=formLeeren;