Select all CheckBoxes -- unresponsive javascript error

I am able to select all checkboxes but if the no of rows are more getting unresponsive javascript error.

can you tell me the better way to check all checkboxes..the approx row count i have is 15000...?

Please help me ..this is urgent...got an prod issue on this..

code which is currently using:
column = 10
rowcount = 15000
for (i=0; i<rowCount; i++){
obj.setCellValue(true,Column,row);
}