Filtering Grid and TextChanged Event of asp.net text box ep 2012

Hello ,

I'm trying to create custom filters to Ax Grid  , so i have a asp.net textBox and a axLookup control like the image bellow 

So when i select the value on lookup i need to filter the grid,  i searched in the web but can't find any example that work's 

And the other point is , when i change the text manually in the textBox for some reason the event TextChanged isn't called , i tested it with a info and the info code never is called 

I m using Dynamics Ax 2012 

Thanks for help