[Energetic Tomboy]

I have an i560....(The newer construction worker phone, but it has the display scene on the outside too). Well Normally I get great connection at my house and normally any other place, but lately I get two bars max at my house and descent connection at other places. Ive heard/know there's a way to change what tower your connection is coming from, but I dont know how. How do you do that?Also, when you lock your keypad (we do it cause my little cousin likes to play with our phones so we lock the pad because he knows how to turn them back on), but when I go to lock mine it asks from the 4-digit password. I was told its the last 4 numbers of your cell number, well I did that and it says that its incorrect. Then I tried the number I use when I get into my voice mail, that didnt work either. If I try for a long time it tells me it will basically shut down my phone, so I stop trying to lock it. How do I figure out what that code is? Should I go to nextel and ask?