problem installing website

hi i have just install boonex script and im getting this message Warning! Dolphin cannot work without mbstring extension. Please go to the Dolphin Troubleshooter and solve the problem. please can anyone help many thanks
Quote · 25 Jan 2009
 
 
Below is the legacy version of the Boonex site, maintained for Dolphin.Pro 7.x support.
The new Dolphin solution is powered by UNA Community Management System.