Google script in HTML block gets rewritten, why?

I am trying to add google map with pin location to a HTML block in a new page block I created. I have been assigned the following script from google for the page script:

<iframe width="425" height="350" frameborder="0" scrolling="no" marginheight="0" marginwidth="0" src="https://maps.google.com/maps?f=q&amp;source=s_q&amp;hl=en&amp;geocode=&amp;q=5454+5+W+Huston+Rd,+Imperial,+CA,+United+States&amp;aq=0&amp;oq=5454+5+Ave+%233,+hust&amp;sll=51.056585,-113.99538&amp;sspn=0.007742,0.013089&amp;ie=UTF8&amp;hq=&amp;hnear=5+W+Huston+Rd,+Imperial,+California+92251&amp;t=m&amp;z=14&amp;ll=32.840024,-115.536086&amp;output=embed"></iframe><br /><small><a href="https://maps.google.com/maps?f=q&amp;source=embed&amp;hl=en&amp;geocode=&amp;q=5454+5+W+Huston+Rd,+Imperial,+CA,+United+States&amp;aq=0&amp;oq=5454+5+Ave+%233,+hust&amp;sll=51.056585,-113.99538&amp;sspn=0.007742,0.013089&amp;ie=UTF8&amp;hq=&amp;hnear=5+W+Huston+Rd,+Imperial,+California+92251&amp;t=m&amp;z=14&amp;ll=32.840024,-115.536086" style="color:#0000FF;text-align:left">View Larger Map</a></small>

After I enter and save it, it is changed to the following and no map shows in the block the script was entered into:

<p><br /><small><a style="color: #0000ff; text-align: left;" href="https://maps.google.com/maps?f=q&amp;source=embed&amp;hl=en&amp;geocode=&amp;q=5454+5+W+Huston+Rd,+Imperial,+CA,+United+States&amp;aq=0&amp;oq=5454+5+Ave+%233,+hust&amp;sll=51.056585,-113.99538&amp;sspn=0.007742,0.013089&amp;ie=UTF8&amp;hq=&amp;hnear=5+W+Huston+Rd,+Imperial,+California+92251&amp;t=m&amp;z=14&amp;ll=32.840024,-115.536086">View Larger Map</a></small></p>

I am certain it is something simple but have searched high and low with no luck. Can someone please tell me what I am doing wrong here.

Do I need to use the API for this to work?

The iframe is being stripped out.  There are a couple of solutions here in the forum.  One is to go into the database and put the code in directly.

Thank you so much for responding to my posts geek_girl. I searched "iframe being stripped out" and found my answer editing the DB. This is a big job for me and again appreciate the tips.