点击到输入框，但不能替换原文字，只能添加到后面

Question

如何将下面的【原创】改为，点击后直接到输入框内，但不能替换输入框内原有文字，只能将【原创】加在原有文字后面

<input name="oTitle" type="text" class="css_input" id="oTitle" value="<%=U.vTitle%>" size="60" <%if len(u.vtitle)=0 and lcl_titles=1 then%>onblur="ChkTitle('');"<%end if%><%if len(u.vtitle)=0 and lcl_titles=2 then%>onblur="ChkTitle($('oCid').value);"<%End If%> /> (250个字符以内)
<label>
<input name="oCommend" type="checkbox" value="1" <%If U.vCommend = 1 Then Response.Write "checked='checked'"%> /> 【原创】 </label>
              <label><input name="oCommend" type="checkbox" value="1" <%If U.vCommend = 1 Then Response.Write "checked='checked'"%> /> 推荐</label>
                <label><input name="oIsComment" type="checkbox" value="1" <%If U.vIsComment = 1 Then Response.Write "checked='checked'"%> /> 评论</label>
                <label><input name="oDisplay" type="checkbox" value="1" <%If U.vDisplay = 1 Then Response.Write "checked='checked'"%> /> 发布</label>

Answer 1

正确答案如下

<input name="oTitle" type="text" class="css_input" id="oTitle" value="<%=U.vTitle%>" size="60" <%if len(u.vtitle)=0 and lcl_titles=1 then%>onblur="ChkTitle('');"<%end if%><%if len(u.vtitle)=0 and lcl_titles=2 then%>onblur="ChkTitle($('oCid').value);"<%End If%> />
<label>
<input name="oCommend" type="checkbox" value="1" <%If U.vCommend = 1 Then Response.Write "checked='checked'"%> />原创
</label>
<script>
    var checkBox = document.querySelector('input[name="oCommend"]');
    var inputBox = document.querySelector('input[name="oTitle"]');
    checkBox.addEventListener('change', function() {
        if (this.checked) {
            inputBox.value += '【原创】';
        } else {
            inputBox.value = inputBox.value.replace('【原创】', '');
        }
    });
</script>
<label><input name="oCommend" type="checkbox" value="1" <%If U.vCommend = 1 Then Response.Write "checked='checked'"%> /> 推荐</label>
<label><input name="oIsComment" type="checkbox" value="1" <%If U.vIsComment = 1 Then Response.Write "checked='checked'"%> /> 评论</label>
<label><input name="oDisplay" type="checkbox" value="1" <%If U.vDisplay = 1 Then Response.Write "checked='checked'"%> /> 发布</label>