convert my new email field to a link

Hi

I have created a new field called "pa_testemail"

I am trying to convert this field to an email link when it displays.

I have used the function shown below - however I want the email link to be inside the textbox and editable.
Is there some other script around I could use?

function ConvertToLink(fldName)
{
var btn = "<a href='javascript: void(0);' onclick=\"window.open(\'http://www.google.com\', \'windowname1\', \'width=600, height=650\'); return false;\" style='color:blue;text-decoration:underline !important'>Test Account</a>";
var ctrl = Xrm.Page.ui.controls.get(fldName)._control;
// Add the new button
 ctrl.get_element().innerHTML += btn;
/Hide the textbox
ctrl.get_element().firstChild.style.display = 'none';
}