4K input scrollBar with resizing slideBar

[gnative]

Hi,
I have created a scroll bar for an input field, it is considerably smaller than using the scrollbar component thou i am have one little problem and it's doing my head in.

this all works except when you delete text from the bottom of the input field , then the slide bar starts jumping.

could anyone help me out here.

I'll post this up when it is completed for all to use
I'll eventually set eveything to resize to the input text field and give it a better skin but wish to sort this bug out first.

Thanks
Shane