Jquery-based code for Image Upload and image size verification and image Preview

Jquery code for verifying the size of uploaded images and previewing the images
Upload image Verification Copy codeThe Code is as follows :*/
Function submit_upload_picture (){
Var file = $ ('file _ C'). value;
If (! /. (Gif | jpg | jpeg | png | gif | jpg | png) $/. test (file )){
Alert ("Image Watermark watermark is one of .gif, jpeg, jpg, and png ")
} Else {
$ ('Both _ form'). action = "file! Upload. action ";
$ ('Both _ form'). submit ();
$ ('Insert _ img '). sethtml (' ');
$ ('Display _ div '). setstyle ('display', 'block ');
$ ('Upload _ div '). setstyle ('display', 'None ');
}
}

Image type and size verification Copy codeThe Code is as follows: // instance 2
Function validate_edit_logo (){
Var file = $ ('file'). value;
If (! /. (Gif | jpg | jpeg | png | gif | jpg | png) $/. test (file )){
Alert ("Image Watermark watermark is one of .gif, jpeg, jpg, and png ")
If (a = 1 ){
Return false;
}
} Else {
Var image = new image ();
Image. src = file;
Var height = image. height;
Var width = image. width;
Var filesize = image. filesize;
$ ('Beforeend'). src = file;
$ ('Div _ regi_right '). setstyle ('display', 'block ');
If (width> 80 & height> 80 & filesize> 102400 ){
Alert ('upload an image of 80*80 pixels or of a size smaller than 100kb ');
If (a = 1 ){
Return false;
}
}
If (a = 1 ){
Return true;
}
}
}

Image Preview Copy codeThe Code is as follows: // instance 3
Function viewimg (index ){
Var name = 'uploadimg '+ index;
Var imgup = $ (name );
Var imgpath = getpath (imgup );
Var local = imgup. value;
Var point = local. lastindexof (".");
// Determine the size of the uploaded file
Var img = document. createelement ("img ");
Img. src = local;
Var filesize = img. filesize;
Img. onload = function () {filesize = this. filesize ;}
When (img. filesize> 5242880 ){
Alert ("the image file is too large! ");
Return false;
}
// Determine whether the image format is used
Var imgname = imgup. value. substring (imgup. value. lastindexof ("."), imgup. value. length );
Imgname = imgname. tolowercase ();
If (imgname! = ". Jpg") & (imgname! = ". Gif") & (imgname! = ". Jpeg") & (imgname! = ". Png") & (imgname! = ". Bmp ")){
Alert ("u8bf7u9009u62e9u56feu7247u6587u4ef6uff0cu8c22u8c22! ");
Imgup. focus ();
// Clear the value in the file www.3ppt.com
Imgup. select ();
Document. selection. clear ();
} Else {
// Display the image
Document. getelementbyid ("sig_preview" + index ). innerhtml = " ";
}
If (index> = 3 ){
Var cnt = index + 1;
$ ("Img" + cnt). style. display = "";
}
}