Problem with converting from ToolStripMenuItem to Button in C#

I am VERY new to C# coming from VB and having an issue.  I have some code that had some options within a toolstipmenu.  I removed these and replaced them with buttons on the form instead.  Below is the code for one of them.  I just took the code and copied it for the button but its not working.  

It dies on....
ToolStripMenuItem item = (ToolStripMenuItem)sender;

Says...
Unable to cast object of type 'System.Windows.Forms.Button' to type 'System.Windows.Forms.ToolStripMenuItem'.

I know its because there is no more toolstripmenu.  As I said I replaced the options on that with buttons.  Any ideas on what is wrong?

Thank you

private void button14_Click(object sender, EventArgs e)
        {
            CurrentSeat.Enabled = true;
            ToolStripMenuItem item = (ToolStripMenuItem)sender;
            LastSeat = (KeyValuePair<LLUUID, LLVector3>)item.Tag;
            Client.Self.RequestSit(LastSeat.Key, LastSeat.Value);
            Client.Self.Sit();
        }

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