<script>
   function ck_business_number(this_s)
   {
   //106-81-97044;
   bs_number = this_s.value.toString();
   bs_number = bs_number.replace(/[^0-9]/g,'');
   result = '';
   bs_1 = bs_number.substr(0, 3);
   bs_2 = bs_number.substr(3, 2);
   bs_3 = bs_number.substr(5, 5);
    if(bs_1.length == 3)
    { result += bs_1;
     if(bs_2.length == 2)
     { result += '-'+bs_2;
       if(bs_3.length == 5)
       { result += '-'+bs_3; }
     }
    }else{
    result = bs_number;
    }
    this_s.value = result;
   }
   </script>

<input name="u_com_number" type="text" id="u_com_number" size="30" maxlength="20" onChange="ck_business_number(this);" onBlur="ck_business_number(this);" >