Recurring Security Warning

[Bizzie47]

I keep getting this security warning when I load a site


"Although this page is encrypted, the information you have entered is to be sent over an unencrypted connection and could easily be read by a third party.
Are you sure you want to continue sending this information?"

I then have the option to continue or cancel.
So far I have cancelled but not too sure of the best way to resolve this.
I am using Firefox

 

[setishock]

When you type in the URL for the website use https:// instead of http://