请问怎么使用onclick触发器
<form   action= " <?php   echo   $file_url;   ?>  "   method= "POST "   name= "subforums "   id= "isubforums ">  
        <p>  
             关键字 
              <input   type= "text "   name= "f_keyword "   value= " "   />  
        </p>  
        <p>  
             页码 
              <input   type= "text "   name= "f_num "   value= " "   />  
        </p>  
        <p>  
              <input   type= "submit "   name= "submit "   value= "Submit "   />  
              <input   type= "button "   onclick= " "   />  
              <input   type= "button "   onclick= "document.subforums.submit(); "   value= "name   submit "   />  
              <input   type= "button "   onclick= "document.isubforums.submit(); "   value= "id   submit "   />  
              <input   type= "button "   onclick= "this.submit(); "   value= "name   submit "   />  
              <input   type= "button "   onclick= "this.submit(); "   value= "id   submit "   />  
        </p>  
  </form>      
 用哪个方法都不行~~郁闷`~~
------解决方案-------------------- <input type= "button " onclick= "document.subforums.submit(); " value= "name submit " />  
 -->  
  <input type= "button " onclick= "document.all.subforums.submit(); " value= "name submit " />      
  <input type= "button " onclick= "document.isubforums.submit(); " value= "id submit " />  
 -->  
  <input type= "button " onclick= "document.getElementById( 'isubforums ').submit(); " value= "id submit " />
------解决方案--------------------you can try this:   
  <html>  
  <form action= "# " method= "POST " name= "subforums " id= "isubforums ">  
  <p>  
 keywords 
  <input type= "text " name= "f_keyword " value= " " />  
  </p>  
  <p>  
 page NO. 
  <input type= "text " name= "f_num " value= " " />  
  </p>  
  <p>  
  <!-- input type= "submit " name= "submit " value= "Submit " /-->  
  <input type= "button " onclick= "javascript:subforums.submit() " value= "name submit " />  
  <input type= "button " onclick= "javascript:document.getElementById( 'isubforums ').submit(); " value= "id submit " />  
  </p>  
  </form>  
  </html>
------解决方案-------------------- <input type= "submit " name= "submit " value= "Submit " />    
 because this node above is existed, you can 't submit with another node.