tick checkbox in Grid

Dear All,

i have a grid with a checkbox. i want set the checkbox from the datasource. if the flag is true then the checkbox can be checked, this way is worked.

the problem is, if i tick another checkbox, the checkbox dont be checked. can you help me?

code :

edit NoYes editMarkTrans(boolean _set, TABLE _TABLE, NoYes value)
{
NoYes ret = value;
TABLE _TABLEJournal;
;

if(TABLE::getPosted(_TABLE.RecId))
ret = noYes::Yes;

if (_set)
{
if(value)
{
ret = NoYes::Yes;
}
else
{
ret = NoYes::No;
}
}

return ret;
}