var bild1 = new Image(); bild1.src="img/agentur_on.gif";
var bild2 = new Image(); bild2.src="img/leistungen_on.gif";
var bild3 = new Image(); bild3.src="img/referenzen_on.gif";
var bild4 = new Image(); bild4.src="img/kontakt_on.gif";

function swapImage( _name, _src ){
	document.images[_name].src = _src;
}


function validate(){
    var ref = document.forms[0].elements;

    if(ref.name.value.length < 1){
            alert("");
            ref.name.focus();
            return false;
    }
    if(ref.vorname.value.length < 1){
            alert("");
            ref.vorname.focus();
            return false;
    }
    if(ref.email.value.indexOf("@") == -1){
            alert("");
            ref.email.focus();
            return false;
    }
    return true;
}

function sendForm(){
    if( validate() ){
        document.forms[0].submit();
    }	
}

function clearForm(num){
	var ref = document.forms[0].elements;
	for( i = 0; i < ref.length; i++ ){
		ref[i].value = "";
	}
}