Question

Why does this table height not function?

<table border=1 bgcolor="green" width=80% height="30%">
    <tr>
        <td rowspan="2" >
            This is 1st row 1st column
        </td>
        <td >
            2
        </td>
    </tr>
</table>

http://jsfiddle.net/zQNS4/

Answer 1

just add the following to your css:

html, body{
    height: 100%;
}

As other said, a table doesn’t have a height-attriute, but most browsers intrepet that anyway. you can see the result on jsfiddle.

The reason you need to do this is that the parent element of anything that should have a height in % must have a height too (as Shadow Wizard said: “30% of what exactly?” – the parent has to have a height).