Security Warning won't let me install SAM

Hi, I'm new here so forgive me if I don't include everything I'm supposed to or if I post incorrectly, I'll get better. I did check all 3 pgs for something to help with my situation b4 posting this question. Until Dec 2012 i'm using Android 1.5 (really old, i know) however, i found this site (slideme dot org) and would love to use it now on my phone(motorola backflip MB300). But (there usually is one :), I d/l the apk(com .slideme .sam .manager- 4.5.apk 2.81 MB), my phone will not let me install it. I get stopped cold by a "Security Warning" as follows: This application comes from an unknown source, and for your security only applications from trusted sources can be installed.Is there some kind of 'techno-junk' that i have to go through to get this installed? or would it jst be easier to download each app i want from the individual app description pages? Any help would be appreciated.

Re: Security Warning won't let me install SAM


To install any application not from your default market, you need to allow third-party installs in your settings (if your mobile carrier has allowed this on your device).

To do so, access your Settings app, then Applications, then checkmark the option "Unknown Sources: Allow installation of non-Market applications".

If you do not see this option, or it will not allow you to check it off, then this means your mobile carrier and/or manufacturer has locked this ability on your phone and you will have to discuss this issue with them.