Problems on DataGrid Update

[wey97]

I have a DataGrid with an Edit/Update/Cancel field but after I click Edit and then click Update I get the following error:

Incorrect syntax near the keyword 'Where'.

On the line -> cmd.ExecuteNonQuery();

Notice I tried adding tics to the Boolean field Admin and the userID field with no luck.

public void DataGrid1_Update(object obj, DataGridCommandEventArgs e)
{

	SqlConnection con = new SqlConnection("server=(LOCAL);database=Reading;trusted_connection=true;");

	string cmdText = "Update [Users] Set " +
		"[UserName]=@UserName, " + 
		"[FullName]=@FullName, " +
		"[Email]=@Email, " +
		"[Admin]=@Admin, " +
		"Where [UserID]=@UserID"; 

	// tried this also
	// string cmdText = "Update [Users] Set " +
	// 	    "[UserName]=@UserName, " + 
	//  	"[FullName]=@FullName, " +
	//  	"[Email]=@Email, " +
	//  	"[Admin]='@Admin', " +
	//  	"Where [UserID]='@UserID'"; 

	SqlCommand cmd = new SqlCommand(cmdText, con);

	string userID = DataGrid1.DataKeys[e.Item.ItemIndex].ToString();
	cmd.Parameters.Add(new SqlParameter("@UserID", userID));

	string userName = ((TextBox)e.Item.Cells[1].Controls[0]).Text; 
	cmd.Parameters.Add(new SqlParameter("@UserName" , userName));

	string fullName = ((TextBox)e.Item.Cells[2].Controls[0]).Text; 
	cmd.Parameters.Add(new SqlParameter("@FullName" , fullName));

	string email = ((TextBox)e.Item.Cells[3].Controls[0]).Text; 
	cmd.Parameters.Add(new SqlParameter("@Email" , email));

	string admin = ((CheckBox)e.Item.Cells[4].Controls[1]).Checked ? "1" : "0";
	cmd.Parameters.Add(new SqlParameter("@Admin" , admin));
	
	cmd.Connection.Open();
	cmd.ExecuteNonQuery();
	cmd.Connection.Close();

	DataGrid1.EditItemIndex = -1;
	BindData();
}