function emojiUnicode (emoji) { 
    var comp; 
    if (emoji.length === 1) { 
        comp = emoji.charCodeAt(0); 
    } 
    comp = ( 
        (emoji.charCodeAt(0) - 0xD800) * 0x400 
      + (emoji.charCodeAt(1) - 0xDC00) + 0x10000 
    ); 
    if (comp < 0) { 
        comp = emoji.charCodeAt(0); 
    } 
    return comp.toString("16"); 
};