Determining which submit button is hit?

I have a form which submits a lot of text and images(file) to an ASP page, and it has two submit buttons on it, i do a onsubmit in the beginning form tag, like this:

<FORM ACTION="preview.asp" ENCTYPE="MULTIPART/FORM-DATA" METHOD="POST" NAME="UPLOADFORM" OnSubmit="return CheckIT();">

here is the bottom of the form

<INPUT TYPE="SUBMIT" NAME="Action" VALUE="PREVIEW">
<INPUT TYPE="SUBMIT" NAME="Action" VALUE="ACCEPT">

here is the CheckIT function

      function CheckIT(){
            
            var LogoOK = 0;
            var InsetOneOK = 0;
            var InsetTwoOK = 0;
            
            if (document.UPLOADFORM.Logo.value == "") {      LogoOK = 1;      }
            if (document.UPLOADFORM.InsetOne.value == "") {      InsetOneOK = 1;      }
            if (document.UPLOADFORM.InsetTwo.value == "") {      InsetTwoOK = 1;      }

            if (LogoOK == 1 || InsetOneOK == 1 || InsetTwoOK) {
                  if(confirm("Mindst et af billedfelterne er tomme!\n\nVild du fortsætte?"))
                        return(true);
                  else
                           return(false);
            }
            else {
                  //document.UPLOADFORM.submit();
                  return(true);
            }
      }

how do i determine which submit button is clicked? this function checks when both buttons are clicked, i only wan't to check when the accept button is clicked???