Question

我目前正在为学校开展一个项目，但我似乎无法将其付诸实践。我试图让scrollingMessage框实际滚动。我测试了一些事情并发现beginPos未定义。我以为我是在定义它，但显然我不是。

<!DOCTYPE HTML>
<html>
<head>
<meta charset="utf-8"> 
<title>Lab10-1</title>

      <script type="text/javascript">
        var adMsg = "** -Danyi's Donuts make great fund-raising items- **"
        var beginPos=0;
        function scrollingMessage() {
          msgForm.scrollingMsg.value = adMsg.substring(beginPos, adMsg.length)+adMsg.substring(0, beginPos);
          beginPos = beginPos+1;
          if(beginPos > adMsg.length) {
            beginPos += 1;
          }
          window.setTimeout("scrollingMessage", 200)
        }


      </script>

<style type="text/css">
<!--
.style1 {
    color: #990000;
    font-weight: bold;
}

.style2 {
    font-family: Arial, Helvetica, sans-serif;
    font-weight: bold;
    color: #0000FE;
    font-size: 14pt;
}

.center-div {
    width: 75%;
    margin-right: auto;
    margin-left: auto;
}
.header-text {
    font-family: Arial, Helvetica, sans-serif;
    font-size: 12pt;
    font-weight: bold;
    text-align: center;
}

.center-items {
    margin-right: auto;
    margin-left: auto;
    text-align: center;
}

.right-align {
    text-align: right;
}

.left-align {
    text-align: left;
}

#footer {
    font-family:Arial, Helvetica, sans-serif;
    font-size:8pt;
    font-weight:bold;
    color: #33C;
    text-align:center;
}

</style>
</head>
<body onload="scrollingMessage();">
<div class="center-div">
  <p class="center-items"><img src="lab10-1banner.jpg" alt="tri star logo" width="750" height="120"></p>
</div>
<div class="center-div">
  <p class="center-items"><span class="style2">Danyi's Donuts Online Ordering System</span></p>
  <form name="donutOrder" class="center-div" id="donutOrder">
    <table class="center-div">
        <tr>
          <td class="right-align">
              <span class="style1">*</span>Types of Donuts:
          </td>
          <td>
              <select name="donutType">
                <option>Select the Type of Donut</option>
                <option value=".19">Glazed</option>
                <option value=".23">Chocolate</option>
                <option value=".24">Jelly Filled</option>
                <option value=".21">Strawberry Sprinkle</option>
                <option value=".18">Danyi Special</option>
              </select>
        </td>
      </tr>
      <tr>
        <td class="right-align">
        <span class="style1">*</span>Enter the number of donuts: </td>
        <td><input type="text" name="count" id="count"></td>
       </tr>
        <tr>
          <td class="right-align">
            <input type="button" value="Calculate">
          </td>
          <td>
            <input type="reset">
          </td>
        </tr>
         <tr>
           <td class="right-align"><span class="style1">*</span>Cost of donuts: </td>
           <td><input type="text" name="donutCost" value=" " size="9"></td>
         </tr>
    </table></form>

    <form id="msgForm">
      <p style="text-align:center"><input type="text" name="scrollingMsg" size="25">
      </input></p>
    </form>


</div>
</body>
</html>

滚动消息框JavaScript

0 个答案: