Is it good to add line-height in body{line-height:1.5} or it would be better if i add separately for tag by tag like p{ line height:1em} etc.

Edit:

body {line-height:in em} create problem with if we put image with float inside

Edit: 24 April 2010:

If i have to add different line heights to elements

like

p {line-height: 1.4}

h1 {line-height:1.6}

h2 {line-height:1.2}

ul li {line-height:1.1}

then shouldn't i use line height in body {line-height:1.4}

if body {line-height:1.4} and h1 {line-height:1.6} then what would be line height for h1?