function CheckForm()
{
if(document.w.certinfo.value=="")
{
alert("证书描述不能为空！")
return false
}
else if(document.w.files.value=="")
{
alert("证书图片不能为空！")
return false
}else {
var file_value = document.getElementById('file').value
alert(isJpg(file_value))
return isJpg(file_value)
}
return true
}
function chkimg(inp)
{
var img=null
if(img)img.removeNode(true)
img=document.createElement("img")
img.attachEvent("onerror",notimg())
img.src=inp
}
function notimg()
{
alert("您插入的不是图片，请重新选择插入！")
}
function isJpg(v) {
if(!v) return
//判断是否为图片的数组，你自己往里面加扩展名吧
var jpg = ['jpg','png']
v = v.split('.')
v = v[v.length - 1]
for(var i in jpg) {
if(jpg[i] == v) {
return true
}
}
return false
}
</script>
网页中表单代码如下：
<form name="w" action="user/upload_cert_success.html" method="post" onSubmit="return CheckForm()" ENCTYPE="multipart/form-data">
<div class="add">
<ul class="ty">证书描述：</ul>
<ul class="cert"><input type="text" name="certinfo" maxlength="100" value="资质认定计量认证证书" /></ul>
</div>
<div class="add1">
<ul class="ty">证书图片：</ul><ul class="certpic"><input type="file" id="file" name="files" /></ul>
</div>
<button type="submit">上传证书</button>
</form>
var g=document.getElementById("div1")var img=new Image()
img.src=g.src
if(img.readyState == 'complete')
{
alert("有图片且图片已加载完成")
} else {
alert('没有图片!')
}
