Dear brother,

asalam alaikum

Asalam alaikum wa rahtmatullahi wa barakatuh = may the peace and mercy of Allah swt be with you.
asalam alaikum= peace be upon you
walikum asalam = peace be upon you too

these are the appropriate islamic form of greetings and a islam sister and brother is rewarded for greeting everyone including people they dislike in such manner.

Jazaka'Allah khair = May Allah swt grant you good.

now i'm guessing next you will ask what is "swt"
swt is the abbreviation of Subhanahu wa ta'ala which means praised and exalted is He (Allah)

when you name or say a prophets name e.g. prophet Muhammad then after the name you will see "saw" which stands for sal'Allahu alayhi wa salam which means peace be upon him and in short we use pbuh.

now regards your first question:
how about sending friendly text messages using cellphone to a muslim sister, is it allowed? i would like to have muslim friends coz i live in a non-muslim country.

dear brother, it does not make a difference whether you approach them in person, send them text messages, write them letters or communicate in sign language it is not encouraged nor allowed in islam...
why dont you leave the sisters alone and make friend's with the brothers first learn new things about islam, make islam and the message of Allah swt your number one priority... thoughts like that, im refering to your question are nothing but whispers of the shaytaan. and shaytaan is nothing but your deadliest enemy.

if you live in a non islamic country then find a local mosque and become a regular visitor and member and interact and make friends with other muslim brothers. then once you have the full lowdown on islam then start to make friends with the sisters since at that stage you would know the limits set by Allah swt and only if you have no ba intentions, cos if your intentions are not clean then Allah swt knows about it more than you do, and the last thing you want to be doing as a new brother in islam is commiting sin and wronging yourself again.

i am a sister and you are a brother, i am contacting you via this forum, but there is no sin in me doing so cos i am doing nothing but helping a fellow muslim brother understand our deen (religion) my intentions are to help you and guide you to the path of Allah swt for you to become steadfast in islam and end up in Jannah Insha'Allah.

so this is what i mean by boundaries. and you will only know and be able to differentiate once you know islam fully and understand its meanings, its message and its way of life. and i pray that Insha'Allah very soon you do.

so for now leave the sisters alone please, no texts, no emails, no letters and no sign language

ma salama