ASP.NET

<br />
     TextBoxThatIsFocuseWhenEnterPressed.Attributes.Add("onKeyPress", "doClick('" + ButtonToTriggerOnEnterPress.ClientID + "',event)")

// Default button code<br />
function doClick(buttonName,e)<br />
    {<br />
//the purpose of this function is to allow the enter key to <br />
//point to the correct button to click.<br />
        var key;<br />
        <br />
        if(window.event)<br />
            key = window.event.keyCode;     //IE<br />
        else<br />
           key = e.which;     //firefox<br />
    <br />
        if (key == 13)<br />
        {<br />
            //Get the button the user wants to have clicked<br />
            var btn = document.getElementById(buttonName);<br />
            if (btn != null)<br />
            { //If we find the button click it<br />
                btn.click();<br />
                if(window.event) event.keyCode = 0;<br />
                <br />
            }<br />
        }<br />
   }

<br />
    <script type="text/javascript" src="JavaScript/DefaultButtonScript.js"></script>