Question

I have two php pages index.php and page2.php.
I want when the first time my website loads it will show index.php which has a search button in it.On clicking the submit button I want to show entire content of page2.php(which now I am showing on page2.php only) on index.php there by removing the need for page2.php.

Answer 1

Change your form so that it reloads the same page:

<form method="post">
    // inputs go here
    <input type="submit" value="Submit" name="submit" />
</form>

Then include an if statement that checks to see if the form has already been submitted:

if (isset($_POST["submit"])){ // form already submitted
    // echo page2.php code here or simply include the code from an external file
}
else {
    // echo the form code above and anything else from the first page here
}