Flash 8.
filter.blurY
Property; a float value that specifies the amount to blur in the y direction, in pixels. Acceptable values are between 0 and 255. This property is defined for Filter objects with a value of "bevelFilter", "blurFilter", "dropShadowFilter", "glowFilter", "gradientBevelFilter", or "gradientGlowFilter" for the filter.name property.
See filter.blurX