LEAVING SALAH IS TANTAMOUNT TO DISBELIEF, Its SHIRK and Its KUFR..

ALLAH SAYS: On that day when Allah will show his sins to human beings and to creation and they will called to prostrate they will not be able to prostrate, As a result their faces will be filled with fear and disgrace will recover their bodies. They used to called to prostrate - Meaning the ATHAN (Call for Prayer) was given, they heard the Athan , they used to be called to pray, whilst they were able to,but they didn't do so.

Ikhwati what does its mean?
Meaning if you fails to pray in this Dunya (Worldly life), Allah will disgrace you, and will punish you, and throw you into JAHANNAM (Hell Fire) in the Akhirah (hereafter).

The first thing that people will say (on)
They will ask the people (who will enter JAHANNAM), What caused you to enter JAHANNAM..??
why they entered JAHANNAM was-
 They will say.. We never used to PRAY..

And that is why the Scholars of Islam, IMAM AHMED says:
      "Anyone misses his one prayer intentionally, then he has became disbeliever."
Anyone misses his one prayer intentionally, Sheikh used to say:
      If you do not intentionally put the alarm clock on, then you have committed an act of SHIRK.
meaning alarm clock on for waking up for FAJR, you know that you can't wake up for Fajr without an alarm clock, you know you need an alarm clock to wake up, but you do not put the alarm clock on then you have committed an act of SHIRK, because SALAH is the only link between us and ISLAM.