regarding softkey board backspace

hi
i need develop a softkey board.
for this i am using gtk as a tool for gui.

all are fine. but when i press a backspace in the softkey board
one last entered character in the textentry should be removed.

i am searching for this.
but i am unable to fine the above.

will you please help me




thanking you

hi
i did like this way

gtk_editable_delete_text (GTK_EDITABLE (softkey_entry), -1, 1);

but this is removing the text from starting mean
EX:
swift(given in the entry)
wift(after click the button)

it is removing first character.

but i need to remove from last character

how can i do this