function gId(idName) {
  if (!document.getElementById(idName)) {
    alert('I cannot find the element with an id of ' + idName + '.');
    return false;
  }
   return document.getElementById(idName);
}

function init() {
    // Toggle Ecommerce Panel
        gId('toggle_ecommerce').onmouseover = function() { 
            gId('features_emailmarketing').style.display = 'none';   
            gId('pricing_emailmarketing').style.display = 'none';
            gId('features_ecommerce').style.display = 'block';
            gId('pricing_ecommerce').style.display = 'block';       
            gId('masthead_left').style.backgroundPosition="0px 0px";
    }

    // Toggle Email Marketing Panel
        gId('toggle_emailmarketing').onmouseover = function() { 
            gId('features_emailmarketing').style.display = 'block';   
            gId('pricing_emailmarketing').style.display = 'block';
            gId('features_ecommerce').style.display = 'none';
            gId('pricing_ecommerce').style.display = 'none';    
            gId('masthead_left').style.backgroundPosition="0px -260px";
    }
}      

window.onload=init;