js 打印部分页面

//打印js
function preview() 
{ 
bdhtml=window.document.body.innerHTML; 
sprnstr="<!--startprint-->"; 
eprnstr="<!--endprint-->"; 
prnhtml=bdhtml.substr(bdhtml.indexOf(sprnstr)+17); 
prnhtml=prnhtml.substring(0,prnhtml.indexOf(eprnstr)); 
window.document.body.innerHTML=prnhtml; 
window.print(); 
} 


var HKEY_Root,HKEY_Path,HKEY_Key; 
HKEY_Root="HKEY_CURRENT_USER"; 
HKEY_Path="\\Software\\Microsoft\\Internet Explorer\\PageSetup\\"; 
//设置网页打印的页眉页脚为空 
function PageSetup_Null() 
{ 
try 
{ 
var Wsh=new ActiveXObject("WScript.Shell"); 
HKEY_Key="header"; 
Wsh.RegWrite(HKEY_Root+HKEY_Path+HKEY_Key,""); 
HKEY_Key="footer"; 
Wsh.RegWrite(HKEY_Root+HKEY_Path+HKEY_Key,""); 
} 
catch(e) 
{} 
} 
//设置网页打印的页眉页脚为默认值 
function PageSetup_Default() 
{ 
try 
{ 
var Wsh=new ActiveXObject("WScript.Shell"); 
HKEY_Key="header"; 
Wsh.RegWrite(HKEY_Root+HKEY_Path+HKEY_Key,""); 
HKEY_Key="footer"; 
Wsh.RegWrite(HKEY_Root+HKEY_Path+HKEY_Key,""); 
} 
catch(e) 
{} 
} 
PageSetup_Default();