var externalLinks = {}
externalLinks.init = function( )
{
    var links
    var i
    var isLink

    links = document.getElementsByTagName( 'a' )

    for( i=0; i<links.length; i++ )
    {
        isLink = links[ i ].href
        if( isLink.indexOf( window.location.hostname ) == -1 && isLink.indexOf( 'javascript' ) == -1 )
        {
            links[ i ].target = '_blank'
        }
    }

}

runOnLoad( externalLinks.init )