function seleccionar(obj){ 
    if(obj.nodeName.toLowerCase()=='textarea' || (obj.nodeName.toLowerCase()=='input' && obj.type=='text')){ 
        obj.select(); 
        return; 
    } 
    if (window.getSelection) {  
        var sel = window.getSelection(); 
        var range = document.createRange(); 
        range.selectNodeContents(obj); 
        sel.removeAllRanges(); 
        sel.addRange(range); 
    }  
    else if (document.selection) {  
        document.selection.empty(); 
        var range = document.body.createTextRange(); 
        range.moveToElementText(obj); 
        range.select(); 
    } 
}