Misir,Egypt...Where did those names come from? ?

Where those name came from ?
What do they mean?
Here,we Egyptians call our country Misir,and we are called,Missri for singular,Misreyeen for plural.
So where have those both names came from ?
Misir and the English name Egypt.

Over the millenniums, Egypt has had many names in many different languages. Today, its official name is Junhuriyaht Misr al-Arabiyah, which in English means The Arab Republic of Egypt. Egyptians themselves refer to Egypt as Misr, though this can also be a name for Cairo. Interestingly, it is common for Egyptians to refer to Egypt as Misr, if they are resident in Cairo, but if outside of Cairo, then they will refer to Cairo as Misr. In a certain respect, this is a custom that dates to the earliest times of ancient Egypt.
Basically, we can examine three groups of names which have applied to Egypt. In the early period of Egypt, during the Old Kingdom, Egypt was referred to as Kemet (Kermit), or simply Kmt , which means the Black land. They called themselves "remetch en Kermet", which means the "People of the Black Land". The term refers to the rich soil found in the Nile Valley and Delta. But it was also sometimes referred to as Deshret, or dshrt , which refers to the "Red Land", or deserts of which Egypt is mostly comprised.
Later, Egyptians referred to their country as "Hwt-ka-Ptah" (Ht-ka-Ptah, or Hout-ak Ptah) , which means "Temple for Ka of Ptah", or more properly, "House of the Ka of Ptah" Ptah was one of Egypt's earliest Gods. As in modern Egypt, this was both a name for the administrative center of Egypt, what we call Memphis today, as well as the name of the country as a whole.
Egypt, as many people of the world refer to the country today, is a derivative of this ancient name. Even today, people who speak one language often change the spelling of words in another language because of the difficulty they may have in pronouncing some of the sounds of that foreign language. Hence, in pronouncing Hwt-ka-Ptah, the Greeks changed this world to Aegyptus (Aigyptos), which they used in their literature as the name of an Egyptian King (perhaps Ramesses, though in a fictional manner), the Nile River and for the country itself. We find the word used by Homer in his famous "Odyssey. We believe the Greeks had difficulties with the Egyptian pronunciation of the letter "H" at the beginning and end of Hwt-ka-Ptah
Today, the word Egyptians often use for their country is Misr.

Miṣr, the Arabic and modern official name of Egypt (Egyptian Arabic: Maṣr), is of Semitic origin, directly cognate with other Semitic words for Egypt such as the Hebrew מִצְרַיִם (Mitzráyim), literally meaning "the two straits" (a reference to the dynastic separation of upper and lower Egypt).The word originally connoted "metropolis" or "civilization" and also means "country", or "frontier-land".
And the English name "Egypt" came via the Latin word Aegyptus derived from the ancient Greek word Aígyptos (Αίγυπτος).

Refrences:
http://www.touregypt.net/featurestories/kmt.htm
http://en.wikipedia.org/wiki/Egypt