Hi Bhumi,
There is no way to that in AJAX mode, however with a simple postback it is possible - you need to modify the Width / Height of the control:
protected void ResizeButton_Click(object sender, EventArgs e)
{
nChartControl1.Width = 800;
}
Our new AJAX controls called ThinWeb will support this feature, however they will available in Vol1.2012.
Best Regards,
Nevron Support Team