Filing with VBA macros form do not valid : I have poor English, sorry :-)

I have a macros to fill form on site. Macro work good, all web form get text from excell and it works fine.
I get problem after filing form with macro. Web forms do not see text there macro inserted. Web forms need to do action with keybord in form. Just after i am doing anything from keyboard in form, it begin see a text, that inserted with macro. For example, typing space from keyboard and deleting it helps to form to be valid.

How can i deleting symbol in form? 
I used getElementsByTagName and getElementsByClassname and with this to commands SendKeys return error. 
For example: 
getElementsByTagName(0).SendKeys"{BACKSPACE}" - return error :-(

Please, help me.