function handleOverlay(bAction){
    if(!this.oOverlay){
        this.oOverlay = document.getElementById('vergunningenkaartwelkom');
    }
    if(typeof(this.bAction) == 'undefined'){
        this.bAction = true;
    }
            
    if(typeof(bAction) != 'undefined'){
        this.bAction=bAction;
    }
    if(typeof(bAction) == 'undefined'){
        console.log(this.bAction)
        console.log(!this.bAction)
        handleOverlay(!this.bAction);
    }
        
    if(bAction == true){
        this.oOverlay.style.visibility = 'visible';
    } else {
        this.oOverlay.style.visibility = 'hidden';
    }
    
}