eclipse startup

i,m using eclipse 3.1 . when i start the eclipse it shows msg box showing :

found jdk1.3, required 1.4.

But i have installed jdk 1.4.2

now i have made a .bat file having following entry

eclipse -vm C:\j2sdk1.4.2\bin\javaw -vmargs -Xmx256m

now when i run the bat file, eclipse starts.

Plz can someone tell me the reason for this.

[381 byte] By [galapagosa] at [2007-10-3 3:31:14]