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//Para detectar si el navegador es 'KONQUEROR / SAFARI / OMNIWEB 4.5+'
if(navigator.vendor == 'KDE' || (document.childNodes &&(!document.all || navigator.accentColorName)&& !navigator.taintEnabled))
{
    alert('Navegador KONKEROR');
}
else
{
    //Para detectar si el navegador es 'OPERA'
    if((window.opera && document.childNodes) || (navigator.userAgent.toLowerCase().indexOf('opera')+ 1))
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        alert('Navegador OPERA');
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        //Para detectar si el navegador es 'MOZILLA / NETSCAPE 6+ / ...'
        if(navigator.product == 'Gecko')
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            if (screen.width == 800)
            {
                //alert('Navegador MOZILLA O NETSCAPE A 800X600');
                document.write("<LINK rel='STYLESHEET' href='NS_800.css' media='SCREEN,PRINT' type='TEXT/CSS'>");
            }
            else if (screen.width == 1024)
            {
                //alert('Navegador MOZILLA O NETSCAPE A 1024X768');
                document.write("<LINK rel='STYLESHEET' href='NS_1024.css' media='SCREEN,PRINT' type='TEXT/CSS'>");
            }
            else if (Screen.width == 1152)
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               document.write("<LINK rel='STYLESHEET' href='NS_1152.css' media='SCREEN,PRINT' type='TEXT/CSS'>");
            }
            else if (screen.width == 1280)
            {
                //alert('Navegador MOZILLA O NETSCAPE A 1280X1024');
                document.write("<LINK rel='STYLESHEET' href='NS_1280.css' media='SCREEN,PRINT' type='TEXT/CSS'>");
            }
            else if (screen.width == 1440)
            {
                //alert('Navegador MOZILLA O NETSCAPE A 1440X900');
                document.write("<LINK rel='STYLESHEET' href='NS_1440.css' media='SCREEN,PRINT' type='TEXT/CSS'>");
            }
            else
            {
                //alert('Navegador MOZILLA O NETSCAPE A 1440X900');
                document.write("<LINK rel='STYLESHEET' href='NS_1440.css' media='SCREEN,PRINT' type='TEXT/CSS'>");
            }
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        {
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                if (screen.width == 800)
                {
                    //alert('Navegador IE 800X600');
                    document.write("<LINK rel='STYLESHEET' href='IE_800.css' media='SCREEN,PRINT' type='TEXT/CSS'>");
                }
                else if (screen.width == 1024)
                {
                    //alert('Navegador IE A 1024X768');
                    document.write("<LINK rel='STYLESHEET' href='IE_1024.css' media='SCREEN,PRINT' type='TEXT/CSS'>");
                }
                else if (screen.width == 1152)
                {
                    document.write("<LINK rel='STYLESHEET' href='IE_1152.css' media='SCREEN,PRINT' type='TEXT/CSS'>");
                }
                else if (screen.width == 1280)
                {
                    //alert('Navegador IE A 1280X1024');
                    document.write("<LINK rel='STYLESHEET' href='IE_1280.css' media='SCREEN,PRINT' type='TEXT/CSS'>");
                }
                else if (screen.width == 1440)
                {
                    //alert('Navegador IE A 1440X900');
                    document.write("<LINK rel='STYLESHEET' href='IE_1440.css' media='SCREEN,PRINT' type='TEXT/CSS'>");
                }
                else
                {
                    //alert('Navegador IE A 1440X900');
                    document.write("<LINK rel='STYLESHEET' href='IE_1440.css' media='SCREEN,PRINT' type='TEXT/CSS'>");
                }
            }
        }
    }
}
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if(history.forward(1))
{
    location.replace(history.forward(1));
}
function disableselect(e)
{
   return false
}
function reEnable()
{
   return true
}
//Para IE
document.onselectstart = new Function ("return false")
//Para NETSCAPE 6+
if (window.sidebar)
{
   document.onmousedown = disableselect
   document.onclick = reEnable
} 
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