how can i dynamically change the BOARDING POINT according to the bus

I have several buses with several  boarding points for each one. i have structed to get boarding points on each bus. i am getting default boarding points.

my concer is

Example :

Bus A have 1,2,3,4 boading points and bus B have 5,6,7,8 boarding points but when select the  bus B i am getting boarding points of Bus A(1,2,3,4).

so how can get bus B Boarding points(5,6,7,8)

My code here:

//<h2 class='TravelAgntNm' title='APSRTC'>APSRTC</h2><a href='javascript&colon;void(0);' rel='' class='canclbtn custom-width cancel' id='canclP249285670'>Cancellation Policy  </a>
  web_reg_save_param("Buses","LB=TravelAgntNm' title='","RB='>","ORD=ALL",LAST);

Random Function

lr_save_string(lr_paramarr_random("Buses"),"Buses1");
lr_output_message("The Selected Bus is ::: %s",lr_eval_string("{Buses1}"));

For Boarding Points:

//<option value="151^MARATHALLI (M) 8453415795  080 - 22971202 / 03 /04 /05 /06^07:45 PM^NEAR BMTC BUS STAND,MARATHALLI,BENGALURU-560037 +918453415795 , 080 - 25401882 , 42099909 SINOSH TOURS & TRAVES OPP  KALAMANDIR^^">MARATHALLI (M) 8453415795  080 - 22971202 / 03 /04 /05 /06-07:45 PM</option>
     web_reg_save_param("Boarding_point","LB=value=\"","RB=^^\">","ORD=ALL",LAST);