Mobile Safari触发Jquery Focus事件时是否不允许在Textarea中输入？

$(\"#text_comment\").live(\'focus\', function () {
    $(this).css(\'height\',\'50px\');
});

$(\"#text_comment\").live(\'focusout\', function () {
    $(this).css(\'height\',\'23px\');
});

$(\'#text_comment, searchinput, timestamp\').live(\'keypress\', function(event) {

      var txt = $(\'#spn\').text();
      var pressed = (txt + String.fromCharCode(event.keyCode));

    var el = this;

    setTimeout(function() {
         var string = $(el).val(); 
         if(string.length < 1) {
            $(el).val(pressed);
         }
    }, 100);

});