Regex! I need to extract from html : Hey please i need to extract the first image from this html:

> [size=5]test.[/size]
 
> [size=5]first.[/size]
 
[img=http://i64.tinypic.com/n337ap.png]
 
> [size=5]Added:[/size]
 
[img=http://i63.tinypic.com/2m578i1.png]
 
[img=http://i65.tinypic.com/ev7653.png]

Example i wanna extract: http://i64.tinypic.com/n337ap.png


Thanks you!