input: [Key-value] mtfLeft=value [Description] 
output: Lets you specify the distance of the Floating or Overlay ad, in pixels or as a percentage, from the left edge of a web page in a browser window. Uses values from -1500 to 1500 as px, pct, or pxc. Notes You can only override this value for Floating or Overlay creatives. For ads with Floating or Overlay creatives, you can append px, pct, or pxc after the integer to specify whether the positioning is determined by pixels or as a percentage. For example, if you use the key-value mtfLeft=40pct, the Floating ad is displayed a distance of 40 percent from the left edge of the web page in a user's browser window. If you do not specify px, pct, or pxc after the integer, pixels are the unit of measure by default.