Hello,

Please let us know how to replicate the error. I created a simple sample about adding row in ColumnSet. It also uses IsRowChecker which works fine. Please see my sample and let me know if you can see the issue in my sample or not.

Regards,
Handy

I am sorry，i follow your sample and it still work incorrectly.please tell me why.thank you

my computer is XP Operating system and IE8 browser,javascript is enabled in my setting.I tried not only in Columnset but also in PlainColumn.edit and delete data is OK,but when add the data,it always returns that error.so i think maybe it is the webgrid bug.

Hello,

Would you mind to provide me a simple runable sample that replicates the error?
I would need more detals to help solving the issue.

Regards,
Handy

i am sorry,i have made the sample but i can't attach file in the browser.maybe it is something wrong with the web.please wait later

I have made the sample,please see it whether the problem will occur or not 

Hello Sayuri,

It works fine when I add the column. Besides, the sample does not show ColumnSet sample.

Regards,
Handy

because when i use this sample,when i add the data and save it,it also occurs that javascript error.could you tell me the probable reason about it? thank you

if (typeof(this.Value)!="boolean") this.Value =td.children[0].checked; },this sentence is in the CommonLibrary\WebGrid\V6_0_7200\webgrid_core.js file.

when i add the data,it always occurs this error

Hello Sayuri,

It's hard to replicate the issue in here. Where was the code snippet added?
At least you must give me a runable sample that can replicate the issue.
Fyi, even though this is a bug in WebGrid6, we will not fix this because WebGrid6 is old product and has discontinued.

Regards,
Handy