function SetTextOnFocus(theTextBox){        
    if(theTextBox.value == 'Zip Code:'){
        theTextBox.value = '';
    }
}

function SetTextOnBlur(theTextBox){        
    if(theTextBox.value == ''){
        theTextBox.value = 'Zip Code:';
    }
}

function EnterClick(buttonName,e) {
    var key;
    
    if(window.event)
        key = window.event.keyCode; //IE
    else
        key = e.which; //firefox

    if (key == 13) {
        //Get the button the user wants to have clicked
        var btn = document.getElementById(buttonName);
        if (btn != null) {
            btn.click();
            if(window.event)
            window.event.keyCode = 0;
        }
    }
}