Small example of JS implementation click download

<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<a   href=""   id=pic1   onclick="savepic();return false;"   style="cursor:hand">Click to download</a>
          <script> 
                  function   savepic()
                { 
                  if(.a1==null)
                        { 
                                  objIframe=("IFRAME"); 
                                  (objIframe); 
                                  =   "<iframe   name=a1   style='width:0;hieght:0'   src="++"></iframe>"; 
                                  re=setTimeout("savepic()",1) 
                          } 
                 else
                        { 
                                  clearTimeout(re) 
                                  pic   =   (,"a1") 
                                  ("SaveAs") 
                                  .(true) 
                          }
                } 
          </script>