验证textarea [英] Validation of textarea

问题描述

如何验证form.ie中的textarea，它不应该是空的或有任何新行，并且如果是这样提出警报

How to validate a textarea in a form.i.e, it should not be empty or have any new lines and if so raise an alert

   <script>
    function val()
    {
      //ifnewline found or blank raise an alert
    } 
   </script>
   <form>  
   <textarea name = "pt_text" rows = "8" cols = "8" class = "input" WRAP ></textarea>
   <input type=""button" onclick="val();"
    </form>

谢谢

Thanks

推荐答案

试试这个：

Try this:

<textarea id="txt" name = "pt_text" rows = "8" cols = "8" class = "input" WRAP ></textarea>

function val()
{
  if (trimAll(document.getElementById('txt').value) === '')
  {
     alert('Empty !!');
  }
} 

function trimAll(sString)
{
    while (sString.substring(0,1) == ' ')
    {
        sString = sString.substring(1, sString.length);
    }
    while (sString.substring(sString.length-1, sString.length) == ' ')
    {
        sString = sString.substring(0,sString.length-1);
    }
return sString;
}

这篇关于验证textarea的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！