Javascript detection (Control) Upload File Size _ image effects

The user's client detects the image size. In actual applications, server-side testing is still necessary.

<Script language = "javascript"> var oForm = new Object (); var oImage = new Image (); oImage. attachEvent ('onload', getSize); oImage. attachEvent ('onerror', doWithError); function checkImage (obj) {oForm = obj; oImage. src = oForm. oFile. value;} function getSize () {var oImgSize = Math. floor (oImage. fileSize/1024); if (oImgSize> 200) {window. alert ('images larger than kb cannot be uploaded! '); OForm. reset () ;}} function doWithError () {window. alert (' error: Please reselect the image to upload! '); OForm. reset ();} script
[Ctrl + A select all Note: If you need to introduce external Js, You need to refresh it to execute]

During the test, you can select a non-image or image with a size greater than kb for the test.