How To Print PDF From Iframe

There are many times requirement to print pdf from Iframe. or PDF embedded in HTML. i will show how i had done printing of PDF from iframe directly to printer.
<?php $printpdfpath="http://mysite.com/upload/sample1.pdf";?>

<div>
<iframe name="my_iframe" id="my_iframe"  width="100" height="100" src="<?php echo $printpdfpath;?>" frameborder="0"></iframe>

<embed
    type="application/pdf"
    src="<?php echo $printpdfpath;?>"
    id="pdfDocument"
    width="100"
    height="100">
</embed>
</div>
first i create an html page at my server and put above code there. which include an Iframe and <embed> to show pdf at html. now
<input type="button"  id="pdf"  value="Print" onclick="printIframe();">

<script>

function printIframe()
{
    if (navigator.userAgent.indexOf("Firefox")!=-1){
        var iframe_window = window.frames["my_iframe"];       
        frame_window.print();
    }
    else if(navigator.userAgent.indexOf("MSIE")!=-1){
        var x = document.getElementById("pdfDocument");
        x.print();       
    }
    else if(navigator.userAgent.indexOf("Chrome")!=-1){
        document.my_iframe.focus();
        document.my_iframe.print();   
    }
    else{   

        // Safari browser or other one   
        //document.getElementById('my_iframe').focus();
        //document.getElementById('my_iframe').onload = setTimeout('iframe.print()',2500);
        //var ifWin = document.getElementById('my_iframe').contentWindow;
        //ifWin.focus();
        //ifWin.print();
        //printpdf();
       
    }   

}

</script>
at above javascript i had put a check for different browser, there is problem with safari to print pdf via Iframe. many time developers face this while using above function which i had commented at Safari section. they print blank pages. so i had use printpdf(); a user define function to call pop window to print.