Fix footer to bottom of page

#footer {
  background-color: red;
  position: fixed;
  bottom: 0px;
  left: 0px;
  right: 0px;
  height: 50px;
  margin-bottom: 0px;
}

div {
  margin: 20px 20px;
}

body {
  margin-bottom: 50px;
}

<div>
  Although most pages on my site have enough content to push the footer to the bottom of the page for most people. I would like to know it's always fixed to the bottom regardless of screen size from now on anyway. I've tried a number of ways such as bottom:
  0x; position:absolute: etc. Never seems to work very well, occasionally pushes the footer out of it's container to fix to the bottom using some of those examples right there. Included is the HTML and CSS for the two parts of the footer (footer & copyright
  bar). They're both inside of a div anyway. I removed my attempts at getting it to stick so people can have a look at it right now and see what the current code is to amend. Although most pages on my site have enough content to push the footer to the
  bottom of the page for most people. I would like to know it's always fixed to the bottom regardless of screen size from now on anyway. I've tried a number of ways such as bottom: 0x; position:absolute: etc. Never seems to work very well, occasionally
  pushes the footer out of it's container to fix to the bottom using some of those examples right there. Included is the HTML and CSS for the two parts of the footer (footer & copyright bar). They're both inside of a div anyway. I removed my attempts
  at getting it to stick so people can have a look at it right now and see what the current code is to amend. Although most pages on my site have enough content to push the footer to the bottom of the page for most people. I would like to know it's always
  fixed to the bottom regardless of screen size from now on anyway. I've tried a number of ways such as bottom: 0x; position:absolute: etc. Never seems to work very well, occasionally pushes the footer out of it's container to fix to the bottom using
  some of those examples right there. Included is the HTML and CSS for the two parts of the footer (footer & copyright bar). They're both inside of a div anyway. I removed my attempts at getting it to stick so people can have a look at it right now and
  see what the current code is to amend. Although most pages on my site have enough content to push the footer to the bottom of the page for most people. I would like to know it's always fixed to the bottom regardless of screen size from now on anyway.
  I've tried a number of ways such as bottom: 0x; position:absolute: etc. Never seems to work very well, occasionally pushes the footer out of it's container to fix to the bottom using some of those examples right there. Included is the HTML and CSS for
  the two parts of the footer (footer & copyright bar). They're both inside of a div anyway. I removed my attempts at getting it to stick so people can have a look at it right now and see what the current code is to amend. Although most pages on my site
  have enough content to push the footer to the bottom of the page for most people. I would like to know it's always fixed to the bottom regardless of screen size from now on anyway. I've tried a number of ways such as bottom: 0x; position:absolute: etc.
  Never seems to work very well, occasionally pushes the footer out of it's container to fix to the bottom using some of those examples right there. Included is the HTML and CSS for the two parts of the footer (footer & copyright bar). They're both inside
  of a div anyway. I removed my attempts at getting it to stick so people can have a look at it right now and see what the current code is to amend. Although most pages on my site have enough content to push the footer to the bottom of the page for most
  people. I would like to know it's always fixed to the bottom regardless of screen size from now on anyway. I've tried a number of ways such as bottom: 0x; position:absolute: etc. Never seems to work very well, occasionally pushes the footer out of it's
  container to fix to the bottom using some of those examples right there. Included is the HTML and CSS for the two parts of the footer (footer & copyright bar). They're both inside of a div anyway. I removed my attempts at getting it to stick so people
  can have a look at it right now and see what the current code is to amend.
</div>
<div id="footer">
  This is footer
</div>