function resizeImg()
{
	// ========================
	// Customise these variables as you wish
	// ========================

	var _resizeWidth  = 500;
	//var _resizeHeight = 500;
	var _resizeClass  = 'detail-img';
	//var _resizeFixHeight = 0;

	var imgArray = document.getElementsByTagName('img');

	for ( var i = 0; i < imgArray.length; i++ )
	{
		var imgObj = imgArray[i];
		if ( imgObj.className == _resizeClass )
		{
			w = imgObj.width;
			h = imgObj.height;
			if( w > _resizeWidth ){

				//f = 1-((w - _resizeWidth) / w);
				_resizeFixHeight = ( ( h / w ) * _resizeWidth );
				//_resizeFixHeight = f;

				imgObj.style.width = _resizeWidth + 'px';
				imgObj.style.height = _resizeFixHeight + 'px';
			}
		}
	}
}

window.onload = resizeImg;