2 Usefull extensions

 $this->html .= $this->basicInputField("user_new_password2", $locale['u135'], "64", $passRequired, "password", FALSE, "user_password");

$this->html .= $this->basicInputField("generated_password", $locale['u135b'], "100", false, $locale['u126']);

 $this->html .= "<tr>\n";
 $this->html .= "<td width='150'></td>\n";
 $this->html .= "<td width='150'><input type='button' class='btn btn-primary' value='".$locale['u135a']."' onClick='randomPassword(8);'></td></tr>\n";
 $this->html .= "<script>";
 $this->html .= "function randomPassword(length) {";
 $this->html.= "var chars = 'abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOP1234567890';";
 $this->html .= "var pass = '';";
 $this->html .= "for (var x = 0; x < length; x++) {";
 $this->html.= "var i = Math.floor(Math.random() * chars.length);";
 $this->html .= "pass += chars.charAt(i);";
 $this->html .= "}";
 $this->html .= "inputform.user_new_password.value = pass;";
 $this->html .= "inputform.user_new_password2.value = pass;";
 $this->html .= "inputform.generated_password.value = pass;";
 $this->html .= "}";
 $this->html .= "</script>";

$locale['u135'] = "Confirm password";

$locale['u135a'] = "Generate password";
$locale['u135b'] = "Generated password";

private $_themeChanged = FALSE;

private $_passwordchange = FALSE;

$this->_setCustomUserFieldsData();

 if ($this->_passwordchange == TRUE) {
 require_once LOCALE.LOCALESET."admin/members_email.php";
 require_once INCLUDES."sendmail_include.php";

 $subject = $locale['email_passwordupd_subject'].$settings['sitename'];
 $replace_this = ["[USER_NAME]", "[PASSWORD]", "[SITENAME]", "[SITEUSERNAME]"];
 $replace_with = [$this->_userName, $this->_newUserPassword, $settings['sitename'], $settings['siteusername']];
 $message = str_replace($replace_this, $replace_with, $locale['email_passwordupd_message']);
 sendemail($this->_userName, $this->_userEmail, $settings['siteusername'], $settings['siteemail'], $subject, $message);
 $this->_passwordchange = FALSE;
 }
 

 if ($_isValidNewPassword === 0) {
 // New password is valid

$this->_passwordchange = TRUE;

$locale['email_create_subject'] = "Account created at ";
$locale['email_create_message'] = "Hello [USER_NAME],<br/>\r\n
Your account at [SITENAME] has been created.<br/>\r\nYou can now login using the following details:<br/>\r\n
Username: [USER_NAME]<br/>\r\nPassword: [PASSWORD]<br/>\r\nRegards,<br/>\r\n[SITEUSERNAME]";

$locale['email_passwordupd_subject'] = "Password changed at ";
$locale['email_passwordupd_message'] = "Hello [USER_NAME],\n
Your password has been succesfully updated<br>Y\r\nYou can now login using the following details:<br/>\r\n
Username: [USER_NAME]<br/>\r\nPassword: [PASSWORD]<br/>\r\nRegards,<br/>\r\n[SITEUSERNAME]";