Show Modal dialog in CRM Entity Form.

Hi Expert,

I have a requirement to show a modal Dialog on the click of ribbon button on an entity, onclick it should show a dialog where user will select some input from the dropdown and returning selected value and saving with the entity form. earlier it was implemented using window.ShowModalDialog function where I was passing URL of html webresource and showing it on the CRM Form, but its not supported in Chrome. I am looking for the alternate way to achieve this.

Thanks