The If statement can be infinitely expanded upon by nesting. Complex decision making can be achieved using this structure.

Syntax
if (condition1 is true)
{
statements to be executed if condition1 is true
   if (condition a is true)
      {
       do something
      }
   else
      {
      do something else
      }
}
else
{
statements to be executed if condition 2 is false
}

Example
<html>
<head>
<title>If else construct</title>
<script>
a = 30
if (a < 50)
{
document.write("a is less than 50")
   if (a < 40)
      {
       document.write("<br>a is also less than 40")
      }
   else
      {
       document.write("<br>but a is greater than 40")
      }
}
else
{
document.write("a is greater than 50")
}
</script>
</head>
</html>

So let's select and copy the above code, and experiment.

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