为什么下面的javascript判断不起作用？真是不明白。解决思路
日期：2014-05-16 浏览次数：20434 次
为什么下面的javascript判断不起作用？真是不明白。
<html>
<head>
<title> 为什么错误？ </title>
<script language= "javascript ">
function chkreg(regf)
{
if (trim(regf.txt_pwdQuestion.value)== " ")
{
alert( "密码提示问题不能为空! ");
regf.txt_pwdQuestion.focus();
return false;
}
regf.submit();
}
</script>
</head>
<body>
<table width= "748 " height= "50 " border= "2 " cellpadding= "1 " cellspacing= "2 " bordercolor= "#EBE9ED ">
<form name= "jmform1 " id= "jmform1 " method= "post " action= "checkUser_Save.asp " onsubmit= "return chkreg(jmform1); ">
<tr>
<td align= "right "> 取回密码问题: </td>
<td> <input name= "txt_pwdQuestion " type= "text " id= "txt_pwdQuestion " size= "30 " maxlength= "18 " class= "reg " value= " ">
<span class= "style11 "> * </span> <span class= "STYLE13 "> (用于忘记密码取回密码) </span> </td>
</tr>
<tr>
<td align= "right "> 取回密码答复: </td>
<td> <input name= "txt_pwdAnswer " type= "text " id= "txt_pwdAnswer " size= "30 " maxlength= "18 " class= "reg " value= "luodiong ">
</tr>
<tr>
<td height= "20 " align= "right "> </td>
<td height= "20 "> <input type= "submit " name= "Submit " value= "提交 " class= "reg1 " "/> </td>
</tr>
</form>
</table>
</body>
</html>
------解决方案--------------------
trim()函数定义了么？
------解决方案--------------------
你是不是少写了document!!!
应该是doucment.regf.txt_pwdQuestion.value
------解决方案--------------------
当初我也犯过晕，为啥asp有trim函数，而javascript没有呢，还得自己定义！
呵呵
------解决方案--------------------
js里确实没有trim这个函数！
------解决方案--------------------
在 <script language= "javascript "> 后加上这句：
function String.prototype.Trim() {return this.replace(/(^\s*)|(\s*$)/g, " ");}
使用方法：
regf.txt_pwdQuestion.value.Trim()
<html>
<head>
<title> 为什么错误？ </title>
<script language= "javascript ">
function chkreg(regf)
{
if (trim(regf.txt_pwdQuestion.value)== " ")
{
alert( "密码提示问题不能为空! ");
regf.txt_pwdQuestion.focus();
return false;
}
regf.submit();
}
</script>
</head>
<body>
<table width= "748 " height= "50 " border= "2 " cellpadding= "1 " cellspacing= "2 " bordercolor= "#EBE9ED ">
<form name= "jmform1 " id= "jmform1 " method= "post " action= "checkUser_Save.asp " onsubmit= "return chkreg(jmform1); ">
<tr>
<td align= "right "> 取回密码问题: </td>
<td> <input name= "txt_pwdQuestion " type= "text " id= "txt_pwdQuestion " size= "30 " maxlength= "18 " class= "reg " value= " ">
<span class= "style11 "> * </span> <span class= "STYLE13 "> (用于忘记密码取回密码) </span> </td>
</tr>
<tr>
<td align= "right "> 取回密码答复: </td>
<td> <input name= "txt_pwdAnswer " type= "text " id= "txt_pwdAnswer " size= "30 " maxlength= "18 " class= "reg " value= "luodiong ">
</tr>
<tr>
<td height= "20 " align= "right "> </td>
<td height= "20 "> <input type= "submit " name= "Submit " value= "提交 " class= "reg1 " "/> </td>
</tr>
</form>
</table>
</body>
</html>
------解决方案--------------------
trim()函数定义了么？
------解决方案--------------------
你是不是少写了document!!!
应该是doucment.regf.txt_pwdQuestion.value
------解决方案--------------------
当初我也犯过晕，为啥asp有trim函数，而javascript没有呢，还得自己定义！
呵呵
------解决方案--------------------
js里确实没有trim这个函数！
------解决方案--------------------
在 <script language= "javascript "> 后加上这句：
function String.prototype.Trim() {return this.replace(/(^\s*)|(\s*$)/g, " ");}
使用方法：
regf.txt_pwdQuestion.value.Trim()
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