从PHP设置热敏打印机尺寸打印

I m trying to print my php/HTML code to print in thermal print size of width 7cm max by onclick print fuction.

However it gives me A4 size print.

Later I tried googling and applied this function as :

<script type="text/javascript">

        function CallPrint(printMe) {
            var prtContent = document.getElementById(printMe);
            var WinPrint = window.open('', '', 'left=0,top=0,width=600,height=400,toolbar=1,scrollbars=1,status=0');
            WinPrint.document.write('<html><head><title></title></head>');
            WinPrint.document.write('<body style="font-family:verdana; font-size:14px;width:300px;height:200px:" >');
            WinPrint.document.write(prtContent.innerHTML);
            WinPrint.document.write('</body></html>');
            WinPrint.document.close();
            WinPrint.focus();
            WinPrint.print();
            WinPrint.close();
            prtContent.innerHTML = "";
        }

    </script>
</head>

but this does the resizing of printable content in an A4 sheet. which doesn't solve my problem.

so , i m here seeking help to "Print my div content in a thermal printer using onclick function"

Any help is appreciated..