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JavaScript client determines file type and size

Source: Internet
Author: User
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<title> submersible non-clogging sewage pump </title>

<meta http-equiv= "Content-type" content= "text/html;charset=gb2312" >
<body>
The following is an example of a client controlling file upload image type and size (note: Because it is a client limit, users can bypass this limitation):
<script language= "JavaScript" >
<!--
var filemaxsize = 50;//Limit uploaded file size, Unit K
function Chkform () {
if (document. hwform.photo.value== "") {alert ("Please select picture! ");d ocument. HwForm.Photo.focus (); return false;}
if (document. hwform.photofilesize.value<=0) {alert ("Please re-select the picture!) ");d ocument. HwForm.Photo.focus (); return false;}
if (document. hwform.photofilesize.value>filemaxsize*1024) {alert ("Picture cannot exceed" +filemaxsize+ "K, please re-select!) ");d ocument. HwForm.Photo.focus (); return false;}
Alert ("Picture type and size is correct, can be submitted! "); return false;
}
-
</script>
<form method= "POST" name= "Hwform" onsubmit= "Return (Chkform ())" enctype= "Multipart/form-data" >
Please select a picture within 50K: <input type= "file" name= "photo" onpropertychange= "if (document. Hwform.photo.value!= ') {document.getElementById (' photoimg '). Src=document. HwForm.Photo.value;} " ><input size= "3" type= "hidden" name= "Photofilesize" value= "1" >
<input type= "Submit" value= "Submission" > <input type= "reset" value= "reset" >
</form>
</body>

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Related Keywords:
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