<script type="text/javascript"> 
var refid='dasdasd,dadsad'; 
var reg =/^([\u0391-\uFFE5\d\w,])*([\u0391-\uFFE5\d\w]+)$/; 
if(refid != "")
{ 
if(reg.exec(refid))
{ 
alert('验证通过'); 
}else 
{ 
alert('验证失败'); 
} 
}
</script>

var reg = /^(/w|[/u4E00-/u9FA5])*$/; 
if(arr=username.match(reg)) 
{ 
ti=1; 
return ture; 
} 
else 
{ 
alert("用户名只允许为英文，数字和汉字的混合,/n请检查是否前后有空格或者其他符号"); 
ti=0; 
return false; 
}

onkeyup="value=value.replace(/[^/u4E00-/u9FA5]/g,'')" onbeforepaste="clipboardData.setData('text',clipboardData.getData('text').replace(/[^/u4E00-/u9FA5]/g,''))" 

onkeyup="value=value.replace(/[^/uFF00-/uFFFF]/g,'')" onbeforepaste="clipboardData.setData('text',clipboardData.getData('text').replace(/[^/uFF00-/uFFFF]/g,''))" 

onkeyup="value=value.replace(/[^/d]/g,'') "onbeforepaste="clipboardData.setData('text',clipboardData.getData('text').replace(/[^/d]/g,''))" 

onkeyup="value=value.replace(/[/W]/g,'') "onbeforepaste="clipboardData.setData('text',clipboardData.getData('text').replace(/[^/d]/g,''))" 

<script> 
function check() 
{ 
if(!isNaN(document.all.form.str.value)) 
{ 
alert("数字"); 
} 
</script> 

<script> 
function check() 
{ 
var str = /[a-zA-Z]/; 
if(str.test(document.all.form.str.value)) 
{ 
alert("字母"); 
} 
} 
</script> 
<form name="form" action="" onsubmit="return check();"> 
<input type=text name=str> 
<input type=submit> 
<form>