c# - I can't use a "kill" process in my code. (its underlined with red) -

i want press button, , when button activated, close application desire. example if open notepad, want press button , close notepad. reason, cannot use kill or close command underlines red. building application in c#. here code.

public eventhandler<speechrecognizedeventargs> srecognized { get; set; }     public form1()     {         initializecomponent();     }             void srecognize_speechrecognized(object sender, speechrecognizedeventargs e)     {         if (e.result.text == "alice present")         {             soundplayer sndplayer = new soundplayer(ai.properties.resources.my_name_is_a_l_i_c_e);             sndplayer.play();         }          if (e.result.text == "open notepad")         {             process notepad = process.start("notepad.exe");         }          if (e.result.text == "close notepad")         {             btnn.performclick();         }     }      private void btnn_click(object sender, eventargs e)     {         process notepad = process.kill("notepad.exe");     } 

lets make simple. create process field , use everywhere:

private process pnotepad;   //process field  void srecognize_speechrecognized(object sender, speechrecognizedeventargs e) {     if (e.result.text == "alice present")     {         soundplayer sndplayer = new soundplayer(ai.properties.resources.my_name_is_a_l_i_c_e);         sndplayer.play();     }      if (e.result.text == "open notepad")     {         //starting process "notepad"         pnotepad = new process();         pnotepad.startinfo.filename = "notepad.exe";         pnotepad.start();     }      if (e.result.text == "close notepad")     {         btnn.performclick();     } }  private void btnn_click(object sender, eventargs e) {     //kill process if running     if(pnotepad != null && pnotepad.hasexited == false)         pnotepad.kill(); }