function mtoOpen( last, first, subject, site, ext ) {
var defSite   = "cnetx";
var defExt    = "com";
var mtoBox    = mtoConcat( mtoDefault( first, 'product' ), last );
var mtoDomain = mtoConcat( mtoDefault( site, defSite ), mtoDefault( ext, defExt ) );

if( mtoBox && mtoDomain ) {
    var mtoAddress  = mtoConcat( mtoBox, mtoDomain, '@' );
    var mtoProtocol = mtoConcat( 'mai', 'to', 'l' );
    var mtoURL      = mtoConcat( mtoProtocol, mtoAddress, ':' );
    
    if( subject ) {
        mtoURL += '?subject=' + subject;
        }
    window.location.replace( mtoURL );
    }

return;
}
function mtoDefault( arg, defValue ) {
return ( ! arg ) ? defValue : arg;
}
function mtoConcat( prefix, postfix, symbol ) {
var retVal = null;
if( prefix ) {
    retVal = prefix;
    if( postfix ) {
        retVal += mtoDefault( symbol, '.' ) + postfix;
        }
    }
return retVal;
}