Editing and saving data in a datastore

Thanks for your reply, Shru_0409. These links were very helpful.
But I'm still not clear about the coding. I've written the following code in 'Itemchanged' event of the datawindow object of the window:

lds_ABC is a global datastore object, from which the data to be displayed is taken.
I want all the changes to be saved and updated in this datastore as well. Thats why I've used the of_update(blob) function. Here, I've used setchanges(blob). But lds_ABC.update() returns -1.
Am I doing the right thing?
Please help me with this code. I'm pretty confused with the functions setitem(), setText(), AcceptText(), etc. Do all these have to be used? I picked these up from the net and some already existing code.

string 	ls_Column
string	ls_Data
 
blob lbl_dw
long ret = 0
 
ls_Column = dwo.Name
 
ls_Data = string(data)
 
this.setitem(row, dwo.name, ls_Data)
this.SetText(ls_Data)
this.AcceptText()
 
this.GetChanges(lbl_dw)
 
ret = lds_ABC.of_update(lbl_dw)
 
If ret = 0 then
	this.Setchanges(lbl_dw)
else
	messagebox("Error saving data to datastore", "Return Code was " +string(ret)) 
end if

                                              

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ls_Data = string(data)
 
//this.setitem(row, dwo.name, ls_Data)
this.setitem(row, 'column_name', ls_Data)
this.SetText(ls_Data)
//..SetText only sets the value in the edit control. When the user changes focus to another row and column, //PowerBuilder accepts the text as the item in the row and column
// this.AcceptText()
// AcceptText can trigger an ItemChanged or an ItemError event.
//AcceptText in the ItemChanged event      Calling AcceptText in the ItemChanged event has no effect.
 
this.GetChanges(lbl_dw)
// lbl_dw what is ?????///
// check the powerbuilder help
 
ret = lds_ABC.of_update(lbl_dw)


pls check the powerbuilder help this will be helpfullll

this.setitem(row, dwo.name, ls_Data)
From the PB help, I saw that dwo.name will return the column name. And it does seem to work.

lbl_dw is the blob that's used to get the changes.

Now the modified data is getting saved in the datastore.
But instead of using the itemchanged event to save each element when its modified, is there a way that I can modify several elements in the window, and then click a 'save' button on the window, wherin all the changes get saved to the datastore together?

1. u r right dwo.name will return the column name but u have to use Describe function... powerbuilde doesn't understand the set column name.
 
2. write your code in updatestart event it will better to handle all condition which u expected

I got my code to work. I moved the getChanges() and of_update() function calls to the 'Save' button's clicked() code. Now I can modify several elements, and on clicking save, all the changes are updated together into the datastore.
Thanks again for your help!