Add/remove curve with checkbox on zedgraph

Hello i am designing a graph that displays a line graph from open file I have got it all working so this isnt the problem, The problem is i want checkboxes to be able to add the line if the check box is checked or to remove the line if the check box is unchecked, i want the graph to refresh on changing the state of the check box to add/remove the line accordingly. I am having trouble with the checkbox and the graph refreshing

if (LCheck.Checked)
{
    LineItem line1 = myPane.AddCurve("LINE1",
        LL, Color.Red, SymbolType.None);
    zgc.AxisChange();
    zgc.Invalidate();
    zgc.Refresh(); 
}

else if (!LCheck.Checked)
{
    LL.Clear();
    zgc.AxisChange();
    zgc.Invalidate();
    zgc.Refresh();
}

Is this the way to do it or is there a better way?