sorting on dhtmlxgrid

if i have column with following record:
B 075,B 121,B 045,B 050,…,M 022,M 026,M 390,M 355,M 045,M 078
if click on header (asc) i want to display like:
B 045,B 050,B 075,B 121,…,M 022,M 026,M 045,M 078,M 355,M 390
if i click again(dec) i want to display like:
M 390,M 355,M 078,M 045,M 026,M 022,…,B 121,B 075,B 050,B 045
i tried using int,str but it doesnt sort the record properly. How can use custom sort method? please replay me ASAP. Insort i want to do sorting with string and integer together.
Some how my triangle doesnt display whenever i clicked on header.

Here you can find a tutorial about creating a custom sorting type: … ngfunction