function changeVisibility (id,value){
        var visib;
        if (document.getElementById(id)){
            if (value == 1){
                visib = "visible";
            }else{
                visib = "hidden";
            }               
            document.getElementById(id).style.visibility = visib;
        }
    }

    function changeBackgroundColor (id,color){
        if (document.getElementById(id)){              
            document.getElementById(id).style.backgroundColor = color;
        }
    }
    
    function disableField (id, value){
        if (document.getElementById(id)){
            document.getElementById(id).disabled = value;
        }
    }
    
    function setValue (id, value){
        if (document.getElementById(id)){
            document.getElementById(id).value = value;
        }
    }
    
    function enableFieldInfo(id){
        changeBackgroundColor(id,"#ffffff");
        disableField(id, false);
    }    
    
    function disableFieldInfo(id){
        changeBackgroundColor(id,"#efeded");
        disableField(id, true);
        setValue(id,"");
    }