function flip_div( active_div_id , hidden_div_id )
{
	if($('#' + hidden_div_id).is(':visible')){
		$('#' + hidden_div_id).hide();
		$('#' + active_div_id).show();
	} else {
		$('#' + active_div_id).hide();
		$('#' + hidden_div_id).show();
	}
}

function IsEmpty(aTextField) {
   if ((aTextField.value.length==0) ||
   (aTextField.value==null)) {
      return true;
   }
   else { return false; }
}

function clearTXT(txtField , stdString)
{
	if(!IsEmpty(txtField) && txtField.value == stdString){
		txtField.value = '';
	}
}

function addTXT(txtField , stdString)
{
	if(IsEmpty(txtField)){
		txtField.value = stdString;
	}
}

function newExcitingAlerts() {
    var oldTitle = document.title;
    var msg = "Ново съобщение!";
    var timeoutId = setInterval(function() {
        document.title = document.title == msg ? ' ' : msg;
    }, 1000);
    window.onmousemove = function() {
        clearInterval(timeoutId);
        document.title = oldTitle;
        window.onmousemove = null;
    };
}