A self-written PHP Upload class

Main functions:
File Upload, get file name, get file size, randomly generate new file name, get file type, Image Generation thumbnail, return the thumbnail file name, return the file name generated after upload, returns the path of the uploaded file.

Class ieb_upload {
Var $ FormName; // file Domain Name
Var $ Directroy; // upload to the directory
Var $ MaxSize; // maximum upload size
Var $ CanUpload; // whether the file can be uploaded
Var $ doUpFile; // name of the uploaded file
Var $ sm_File; // The Name Of The thumbnail.
Var $ Error; // Error parameter

Function ieb_upload ($ formName = '', $ dirPath ='', $ maxSize = 2097152) // (1024*2) * 1024 = 2097152 is 2 M
{
Global $ FormName, $ Directroy, $ MaxSize, $ CanUpload, $ Error, $ doUpFile, $ sm_File;
// Initialize various parameters
$ FormName = $ formName;
$ MaxSize = $ maxSize;
$ CanUpload = true;
$ DoUpFile = '';
$ Sm_File = '';
$ Error = 0;

If ($ formName = ''){
$ CanUpload = false;
$ Error = 1;
Break;
}

If ($ dirPath = ''){
$ Directroy = $ dirPath;
} Else {
$ Directroy = $ dirPath .'/';
}
}

// Check whether the file exists
Function scanFile ()
{
Global $ FormName, $ Error, $ CanUpload;

If ($ CanUpload ){

$ Scan = is_readable ($ _ FILES [$ FormName] ['name']);

If ($ scan ){
$ Error = 2;
}

Return $ scan;
}
}


// Get the file size
Function getSize ($ format = 'B ')
{
Global $ FormName, $ Error, $ CanUpload;

If ($ CanUpload ){

If ($ _ FILES [$ FormName] ['SIZE'] = 0 ){
$ Error = 3;
$ CanUpload = false;
}

Switch ($ format ){