function popcenter(uri,wi,he,poptype) {
    var strscroll=",resizable=0";
    if(poptype=="narrow"){
        wi=parseInt(wi)+16; he=parseInt(he)+16;       
        var strscroll=",resizable=0";
    }else if(poptype=="picture"){
        wi=parseInt(wi)+44; he=parseInt(he)+100;
        var strscroll=",resizable=1";
    }else if(poptype=="wide"){
        wi=parseInt(window.screen.availWidth*.8); he=parseInt(window.screen.availHeight*.95);
        var strscroll=",scrollbars=1,resizable=1";
    }else{
        wi=parseInt(wi)+16; he=parseInt(he)+16;
        var strscroll=",resizable=1";
    }
    var w=(window.screen.availWidth-wi)/2-16;
    var h=(window.screen.availHeight-he)/2-16;
    if(wi>window.screen.availWidth-24 || he>window.screen.availHeight-24){ strscroll=",scrollbars=1,resizable=1";}
    str="width="+wi+",height="+he+",top="+h+",left="+w+""+strscroll+"";

    zoom=window.open(uri,"zoom",str);
}