今天的代码

1.表格事先被隐藏，checkbox被选中后显示出来，checkbox不选后表格重新隐藏

<table cellpadding="0" cellspacing="0" width="300px">
    <tr><td class="paddL f4">污染物</td></tr>
    <tr><td class="lfrb" style="font-size:12px" width="290px"><input id="zd1" type="checkbox" name="kml" value="pwk" onclick="chg('zd1','yc1')">污染物扩散模型</td></tr>
    <tr><td class="lfrb" id="yc1" style="display:none">
        <table cellpadding="0" cellspacing="10" >
          <tr></tr>
        </table>
  </td></tr></table>

 

function chg(x,y)
{
    if(document.getElementById(x).checked==true)
    {
        
        document.getElementById(y).style.display="";
    }
    else
    {
        document.getElementById(y).style.display="none";
    }
}

  2.下拉列表改变的时候，改变提示信息

 <table cellpadding="0" cellspacing="10" align="left" >
          <tr><td class="th1" width="50px">河流网ID</td>
            <td>
              <select id="river" name="yellowID" onchange="chg2()" >
                <option selected="selected">请选择</option>
                <option value="G3">1</option>
                <option value="G4">2</option>
            </select>    
            </td>
            
            <td width="75px" ><input type="submit" value="取到河流形状"/></td>
          </tr>
          <tr>
            <td id="show1" class="th1" colspan="3" style="display:none"><span style="display:none" id="n1">小浪底to利津，764,000m</span><span id="n2" style="display:none">花园口to利津，632,000m</span></td>
          </tr>
        </table>
    </td></tr>
  </table>

 

function chg2(){
   
    if(document.getElementById("river").value=="G3")
        {
            document.getElementById("show1").style.display="";
            document.getElementById("n1").style.display="";
            document.getElementById("n2").style.display="none";
        }
    else if(document.getElementById("river").value=="G4")

        {
            document.getElementById("show1").style.display="";
            document.getElementById("n1").style.display="none";
            document.getElementById("n2").style.display="";
        }
    else{document.getElementById("show1").style.display="none";
        document.getElementById("n1").style.display="none";
        document.getElementById("n2").style.display="none";
    }
}