Cant see SQL Server Agent in SSMS I have SSMS 2012 installed on my laptop, and SQL Server 2012 on my hosting, but when i try to schedule a sql job i didn't find "SQL Server Agent" in the left side list!!?
If you have Management Studio Express installed (any version prior to SQL Server 2012 SP1), it simply doesn't contain any facility for SQL Server Agent (no matter which edition you're trying to manage). You can fix this by getting the very latest version from here:

http://www.microsoft.com/en-us/download/details.aspx?id=43351

You want the file SQLManagementStudio_x64_ENU.exe (or the one with x86 in the name if you have a really old 32-bit machine). This is the first version of Management Studio that has been offered fully functional and license-free.

Once you install this version of Management Studio, you will have access to SQL Server Agent when managing any instances of the SQL Server engine that support SQL Server Agent. Of course that won't help you create jobs on instances of SQL Server Express, since it doesn't have Agent at all.