function initnavformurl()
{
    var s = window.location.href;
    var p = s.indexOf("?");	
    if( p >= 0 ) s = s.substring(0,p);
    $("navform").action = s;
}
initnavformurl();

function firstpage()
{   
	var gotopagefield = $("qi.gotopage");
    gotopagefield.value=1;
    $("navform").submit();
}
function prevpage()
{
	var gotopagefield = $("qi.gotopage");
    gotopagefield.value=parseInt(gotopagefield.value)-1;
    $("navform").submit();
}
function nextpage()
{
	var gotopagefield = $("qi.gotopage");
    gotopagefield.value=parseInt(gotopagefield.value)+1;
    $("navform").submit();
}
function lastpage()
{
	var gotopagefield = $("qi.gotopage");
	var totalpagesfield = $("qi.totalpages");
    gotopagefield.value=totalpagesfield.value;
    $("navform").submit();
}

function gotopage(n)
{
	var gotopagefield = $("qi.gotopage");
    gotopagefield.value=n;
    $("navform").submit();
}

function direct_goto_page()
{
	var maxpages = parseInt($("qi.totalpages").value);
	var gotopagefield = $("qi.gotopage");

    if( $("directgotopage").value != "") 
    { 
        if( !nav_checkpageno($("directgotopage").value) ) 
        {
            alert("页码不正确");
            return false;
        }
        
        var pno = parseInt($("directgotopage").value);
        if( pno <= 0  || pno > maxpages ) 
        {
            alert("页码不正确");
            return false;
        }
        
        gotopagefield.value=$("directgotopage").value;
        $("navform").submit();
    }
    
    return false;
}
function nav_checkpageno(value,mode)
{
  if( value == null || value.length == 0 || isNaN(value) ) return false ;
  if( new RegExp("[^0-9]").test(value) ) return false ;
  return true ;
}