I need a js code snippet - open to bidding

I need to programmatically submit a form on a webpage with javascript. I have a chrome extension, if your code snippet works it will be added to my project. The url is here : [login to view URL] What I need is to set the investment value to $1, $5, $10, $20 as I wish in the picture here look : [login to view URL] Currently I can set the value in the input textbox field, but the forms won't take automatic entry by javascript without user interaction. So I need someone who can change the input field value with js. Then programmatically send the order by clicking with code on call or put button. I won't touch mouse of keyboard. Everything will need to be automatic.