如果提供两个条件，如何启用/禁用提交按钮：检查输入无线电和填写输入文本

I have this form:

我有这样的形式:

<form name="myform" method="post">
  <input class="class_x" type="radio" name="name_1" value="value_1" id="id_1"/><br/>
  <input class="class_x" type="radio" name="name_2" value="value_2" id="id_2"/><br/>
  <input class="class_x" type="radio" name="name_3" value="value_3" id="id_3"/><br/>
  <input onkeyup="checkFormsValidity();" id="input_id" type="text" name="input_name" value="" required/><br/>
  <input type="submit" name="submit_name" value="OK" class="submit_class" id="SubmitButton"/>
</form>
<form name="myf