function getStyleProp(elem, prop) {
  if (window.getComputedStyle) {
    return window.getComputedStyle(elem, null).getPropertyValue(prop);
  } else if (elem.currentStyle) {
    return elem.currentStyle[prop]; // IE
  }
}
window.onload = function () {
  var d = document.createElement("div"); // Create div
  d.className = "layout"; // Set class = "layout"
  alert(getStyleProp(d, "color")); // Get property value
};

Alternatively, if you want to determine the CSS property inherited from a stylesheet without considering any inline styles, the following function can be used:

function getNonInlineStyle(elem, prop) {
  var style = elem.cssText; // Cache the inline style
  elem.cssText = ""; // Remove all inline styles
  var inheritedPropValue = getStyleProp(elem, prop); // Get inherited value
  elem.cssText = style; // Add the inline style back
  return inheritedPropValue;
}

By leveraging these techniques, developers can dynamically adjust the CSS properties of elements, manipulate their presentation, and gain a deeper understanding of the page's styling.