PHP anti-injection security code

To determine whether the passed variable contains illegal characters, we put the following code into a public file, such as security. inc. in php, every file contains this file, so that all variables submitted by any program can be filtered out, which achieves our effect once and for all. Brief description :/*************************
Note:
Determines whether the passed variable contains invalid characters.
Such as $ _ POST and $ _ GET
Function: Anti-injection
**************************/

The code is as follows:

// Invalid characters to be filtered
$ ArrFiltrate = array ("'", ";", "union ");
// The url to be redirected after an error occurs. If this parameter is left blank, the previous page is displayed by default.
$ StrGoUrl = "";
// Whether the value in the array exists
Function FunStringExist ($ StrFiltrate, $ ArrFiltrate ){
Foreach ($ ArrFiltrate as $ key => $ value ){
If (eregi ($ value, $ StrFiltrate )){
Return true;
}
}
Return false;
}

// Merge $ _ POST and $ _ GET
If (function_exists (array_merge )){
$ ArrPostAndGet = array_merge ($ HTTP_POST_VARS, $ HTTP_GET_VARS );
} Else {
Foreach ($ HTTP_POST_VARS as $ key => $ value ){
$ ArrPostAndGet [] = $ value;
}
Foreach ($ HTTP_GET_VARS as $ key => $ value ){
$ ArrPostAndGet [] = $ value;
}
}

// Verification starts
Foreach ($ ArrPostAndGet as $ key => $ value ){
If (FunStringExist ($ value, $ ArrFiltrate )){
Echo"