请教"保存"的问题怎么样做到?

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<HTML>
<HEAD>
<META http-equiv="Content-Type" content="text/html; charset=UTF-8">
<META name="GENERATOR" content="IBM WebSphere Studio Homepage Builder Version 10.0.0.0 for Windows">
<META http-equiv="Content-Style-Type" content="text/css">
<TITLE></TITLE>
<SCRIPT LANGUAGE="JavaScript">
<!--
function InitMsgBox(obj){
strsrc = obj.value;td1.innerHTML = "<img id='img' src=\"" + strsrc + "\" onload='changeImage(640,480)' style='display:none'>"
}
  function changeImage(w,h) {
try{
  document.getElementById("img").width = w;
  document.getElementById("img").height = h;
  document.getElementById("img").style.display = "";
}catch(e){
}
}
//-->
</SCRIPT>
</HEAD>
<BODY><BR>
<CENTER>
<TABLE border="6">
  <CAPTION align="bottom"></CAPTION>
  <TBODY>
    <TR>
      <TD align="center"><INPUT type="file" style="background:#ffffff" name="getfile" id="getfile" onunblur="getfile_onclick" class="btn" onchange='javascript:InitMsgBox(this)'><INPUT type="button" value="保存" onclick=""></TD>
    </TR>
    <TR>
      <TD id="td1" width="320" height="240"></TD>
    </TR>
  </TBODY>
</TABLE>
<INPUT type="button" value="40" onClick="changeImage(80,60)">
<INPUT type="button" value="160" onClick="changeImage(160,120)">
<INPUT type="button" value="320" onClick="changeImage(320,240)">
<INPUT type="button" value="Default" onClick="changeImage(640,480)">
</CENTER>
</BODY>
</HTML>