static int flag = 0;
protected void Page_Init(object sender,EventArgs e)
{
ImageButton.ImageUrl = "BlubOff.jpg";
}
protected void ImageButton_Click(object sender,EventArgs e)
{
if(flag == 0)
{
ImageButton.ImageUrl = "BlubOn.jpg";
flag = 1;
}
else if(flag == 1)
{
ImageButton.ImageUrl = "BlubOff.jpg";
flag = 0;
}
}