Redirect to another aspx page when message box button is click

Hi ,I am doing a message box that when user clicks on the Ok button, it will redirects to another aspx page. However, I do not know what is wrong with the code.
This is the code that I have input in:

protected void btnUpload_Click(object sender, EventArgs e) 
System.Windows.Forms.MessageBox.Show("The Category Description has been repeated, please make the necessary changes! ", "Template", MessageBoxButtons.OK, MessageBoxIcon.None); 
if (MessageBoxButtons.OK == true) 


The problem is you are trying to display a windows form message box on a website, which will not work. You need to use some sort of javascript modal popup or alert()

^^^^ what NightStalker said.

Really, you cannot ever use anything from the System.Windows.Forms namespace. That is for local Windows applications - not web at all.

You may want to look at the ConfirmButton from the AJAX Control Toolkit: