Problem Reading osm into postgis


 i have downloaded posgis and postgresql and also osm2pgslq. I am trying to read my .osm file into my db using the command osm2pgslq -a map.osm. When i hit the enter button, it says 

Using projection SRS3395 (WGS84 Marcator)
settingup table: planet_osm_point
connection to the database failed: fe_sendauth: no password supplied
Error occrured, cleaning up.

When i downloaded the osm2pgslql file it did not ask me for any password. How exactly can i rectify this so that i can read my .osm data into my db?

Another proble i am getting is that, when i click on start server icon, i get something called
System error 5 has occured
Access is denied
press return to continue

after pressing returns it simply closes the comman prompt

One final problem i get is that when i try to use the SQL Shell(pgsql) prompt it askes me for the following:

server [localhost]: 5432
Database [postgres] postgis(i enter this because on pgAdmin i can see this as a db)
Port [5432]: 5432
Username [postgres]: enter my name

and i get the following message:
psql: could not translate host name"5432" to address unkown host

can somebody tell me why i get the above message and how i can rectify this.