function setAlpha (obj, alpha) {
    obj.style.visibility = (alpha > 0) ? 'visible' : 'hidden'
    if (alpha > 0 && alpha < 100) {
      if (isLessThanIE7) {
        const src = obj.getAttribute('pngSrc')
        if (!isNullish(src) && (
          src.includes('AlphaBar.png') || src.includes('Bars.png') || src.includes('Maps.png')
        )) {
          obj.style.filter = 'progid:DXImageTransform.Microsoft.AlphaImageLoader(src=\'' + src +
          '\', sizingMethod=\'scale\') progid:DXImageTransform.Microsoft.Alpha(opacity=' + alpha + ')'
        } else obj.style.opacity = toFixedNumeric(alpha / 100, 4)
      } else obj.style.opacity = toFixedNumeric(alpha / 100, 4)
    } else if (alpha === 0 || alpha === 100) {
      if (isLessThanIE7) {
        const src = obj.getAttribute('pngSrc')
        if (!isNullish(src) && (
          src.includes('AlphaBar.png') || src.includes('Bars.png') || src.includes('Maps.png')
        )) {
          obj.style.filter = 'progid:DXImageTransform.Microsoft.AlphaImageLoader(src=\'' + src +
          '\', sizingMethod=\'scale\')'
        } else obj.style.opacity = ''
      } else obj.style.opacity = ''
    }
  }
@param {external:jQuery} obj
@param {Float} alpha
@returns {void}