Print Web Page through javascript in ASP.Net

function doPrint() {

bdhtml=window.document.body.innerHTML;
sprnstr="";
eprnstr="";
prnhtml=bdhtml.substr(bdhtml.indexOf(sprnstr)+17);
prnhtmlprnhtml=prnhtml.substring(0,prnhtml.indexOf(eprnstr));
window.document.body.innerHTML=prnhtml;
window.print();

}