Upload an image using the HTML file control, and use js to determine and limit the image format, type, and size. 1 function checkfile (F, P)
2 {
3 // determine the image size
4var IMG = NULL;
5img = Document. createelement ("IMG ");
6document. Body. insertadjacentelement ("beforeend", IMG );
7img. style. Visibility = "hidden ";
8img. src = F;
9var imgwidth = IMG. offsetwidth;
10var imgheight = IMG. offsetheight;
11if (P. Name = "upfile_photo1 ")
12 {
13if (imgwidth! = 68 | imgheight! = 68)
14 {
15 alert ("the size of the thumbnail should be 68X68 ");
16}
17}
18if (P. Name = "upfile_photo2 ")
19 {
20if (imgwidth! = 257 | imgheight! = 351)
21 {
22 alert ("the image size should be 257x351 ");
23}
24}
25if (P. Name = "upfile_photo3 ")
26 {
27if (imgwidth! = 800 | imgheight! = 800)
28 {
29 alert ("the size of the big image should be 800x800 ");
30}
31}
32 // determine the image type
33if (! /\. (GIF | JPG | JPEG | BMP) $/. Test (f ))
34 {
35 alert ("Image Watermark watermark is one of .gif, JPEG, JPG, and BMP ")
36 return false;
37}
38 return true;
39}
Related HTML code
1 <input type = "file" id = "upfile_photo1" runat = "server" name = "upfile_photo1"
2 size = "35" onpropertychange = "checkfile (this. value, this)"> thumbnail <br/>
3 <input type = "file" id = "upfile_photo2" runat = "server" name = "upfile_photo2"
4 size = "35" onpropertychange = "checkfile (this. value, this)"> center chart <br/>
5 <input type = "file" id = "upfile_photo3" runat = "server" name = "upfile_photo3"
6 size = "35" onpropertychange = "checkfile (this. value, this)"> large image <br/>
