Easy way to change the title name of block base on the language people select.
If a user use english the title to be in english, if the user choose thai the title in thai.
Here is the quickly way !!!

Open the file mainfile.php
in function blocks($side) {
...
Search:
$title = $row[title];
Replace with:
$title = translate($row[title]);
...
}

And your language file (language/lang-XXX.php)
in function translate($phrase) {
...
Add your title name of block in your language etc.
case "Languages": $tmp = "ภาษา"; break;
case "Who's Online": $tmp = "ผู้ใช้งานขณะนี้"; break;
case "Modules": $tmp = "เมนูหลัก"; break;
case "Survey": $tmp = "แบบสำรวจ"; break;
case "Login": $tmp = "เข้าระบบ"; break;
case "Search": $tmp = "ค้นหา"; break;
case "Information": $tmp = "แหล่งข้อมูล"; break;
case "Old Articles": $tmp = "บทความที่ผ่านมา"; break;
case "Big Story of Today": $tmp = "เรื่องใหญ่ประจำวัน"; break;
...
}