How to click left button with C#

using System;
using System.Windows.Forms;
using System.Runtime.InteropServices;

public class Form1 : Form
{
   [DllImport("user32.dll",CharSet=CharSet.Auto, CallingConvention=CallingConvention.StdCall)]
   public static extern void mouse_event(long dwFlags, long dx, long dy, long cButtons, long dwExtraInfo);

   private const int MOUSEEVENTF_LEFTDOWN = 0x02;
   private const int MOUSEEVENTF_LEFTUP = 0x04;
   private const int MOUSEEVENTF_RIGHTDOWN = 0x08;
   private const int MOUSEEVENTF_RIGHTUP = 0x10;

   public Form1()
   {
   }

   public void DoMouseClick()
   {
      //Call the imported function with the cursor's current position
      int X = Cursor.Position.X;
      int Y = Cursor.Position.Y;
      mouse_event(MOUSEEVENTF_LEFTDOWN | MOUSEEVENTF_LEFTUP, X, Y, 0, 0);
   }

   //...other code needed for the application
}