how to create custom if else statements in templates

[GotVtec]

I created a variable in the global.php file that radomly selects a number, 1 or 2. In my templates I would like to create an if else loop that will display ad1 if the variable equals 1, or ad2, if the variable equals 2.

Is there a tutorial for something like this?

[WhaLberg]

<if condition="$yourvar == anothervar">your codes<else />your other codes </if>

For example if your variable returns as true or false, basically you need this:
<if condition="$yourvar">your codes</if>

You can also use 'else' there.