Take and save photo from webcam in one button ASP.NET

Question

I try to create a webpage taking and saving the members' photo with their rate about our services. And I wanna do this in one button (take photo then save). I had created 2 button types: Capture photo and Rate button (Good, Bad, No idea) but I couldn't make it in one button like I said.

My sample code:

function takePhoto()
{
  Webcam.snap(function (data_uri) {
    imageObj_BG.src = data_uri;
    init('BG', '');
  });
}

function savePhoto()
{
  var image_NEW = document.getElementById("canvas").toDataURL("image/png");
  image_NEW = image_NEW.replace('data:image/png;base64,', '');
  $("#<%=hidImage.ClientID%>").val(image_NEW);
  alert('Thanks for your comment!');
}

<input type=button value="Capture Photo" onClick="takePhoto()">

<asp:ImageButton ID="ImageButton2" runat="server" Height="200px" Width="200px" ImageUrl="~/Images/Happy.gif" OnClientClick="savePhoto();return true;" OnClick="ImageButton2_Click" ImageAlign="Middle" />