html:

<textarea id="markcontent" class="input2style textarec" name="content" rows="2" cols="56" onkeyup="ShowInputNum(this)"></textarea>

js:

function ShowInputNum(obj) {
            var length = $(obj).val().length;
            
            //var pattern = "/^([\u4e00-\u9fa5A-Za-z0-9,.?!，。？！])*$/";  
            var s = $(obj).val();  
            if(!/^([\u4e00-\u9fa5A-Za-z0-9,.?!;，。？！、；])*$/.test(s)){
                alert("存在特殊字元");
                return false;
            }