function BuyTr(form_id)
{	
    isTrackSelected = false;
    
	form = $(form_id);
	for(i = 0; i < form.elements.length; i++){
		if(form.elements[i].type == "checkbox" && form.elements[i].checked){			
			isTrackSelected = true;
            break;
        }
	}
    
    if(!isTrackSelected){
        showDialog('Message', 'Please, select tracks for purchase.', 'warning');               
		return false;
	}
    
    new Ajax.Request('/AjCheckBalance',
    {        
        parameters: $(form_id).serialize(),
        onSuccess: function(transport){
            var response = transport.responseText.evalJSON();
            if(response.status){
                form.action.value = 1;
                form.submit();           
            }else{
                showDialog('Message', response.status_msg, 'warning');            
            }           
        }        
    });  
	
	return false;
}

function RemoveTr(form_id)
{
    isTrackSelected = false;
    
	form = $(form_id);
	for(i = 0; i < form.elements.length; i++){
		if(form.elements[i].type == "checkbox" && form.elements[i].checked){
            isTrackSelected = true;
            break;			
		}
	}

	if(!isTrackSelected){
        showDialog('Message', 'Please, select tracks for removal.', 'warning');        
		return false;
	}
    
	form.action.value = 2;
	form.submit();
	return true;
}

var check = false;

function SelectTracks(form_id)
{
	form = $(form_id);
	for(i = 0; i < form.elements.length; i++){
		if(form.elements[i].type == "checkbox"){
            if( check ){
                form.elements[i].checked = false;
            }else{
                form.elements[i].checked = true;
            }
		}
	}
	check = !check;	
	return ;
}

function CheckAlbum(control, form_id)
{    
    album_id = control.value;
    form = $(form_id);
    for(i = 0; i < form.elements.length; i++ ){
		if(form.elements[i].type=="checkbox" && form.elements[i].id == album_id){
            if( control.checked ){
                form.elements[i].checked = true;
            }else{
                form.elements[i].checked = false;
            }
		}
	}
    return;
}

function CheckTrack(control, form_id)
{
    album_check = true;
    album_id = control.id;
    form = $(form_id);
    for(i = 0; i < form.elements.length; i++){
		if(form.elements[i].type == "checkbox" && form.elements[i].id == album_id && form.elements[i].checked == false){
            album_check = false;
            break;            
		}
	}
    
    $('album_' + album_id).checked = album_check;    
    return;
}