window.addEvent('domready', function(){
    var el = $('ctrl_1');
    var val = 'Suchbegriff';
    
    el.addEvents({
        click: function(){
            if(el.value == val) el.value = '';    
        },
        blur: function(){
            if(el.value == '') el.value = val;    
        }
    });
});