Siebel 数学运算

if(quotaId != ""){
    with(bcQuota){
        SetViewMode(AllView);
        ActivateField("Id");
        ActivateField("Available Amount");
        ActivateField("Occupation Amount");
        ClearToQuery();
        searchExpr = "[Id] = ‘" + quotaId + "‘";
        SetSearchExpr(searchExpr);
        ExecuteQuery(ForwardOnly);
        if(FirstRecord())
        {
            availAmount = ToNumber(GetFieldValue("Available Amount"));
            occupAmount = ToNumber(GetFieldValue("Occupation Amount"));
            //availAmount = availAmount + Math.abs(sumCSP-sumNRC);
            var minResult = Math.abs(sumCSP-sumNRC);
            if((occupAmount-minResult)< 0.0000001){
                //TheApplication().RaiseErrorText(occupAmount +"------" +minResult);
                occupAmount = 0;
            }else{
                occupAmount = occupAmount-minResult;
            }
            //SetFieldValue("Available Amount",availAmount);
            SetFieldValue("Occupation Amount",occupAmount);
            WriteRecord();
        }//end if
    }//end with
}