Can I delete old versions of JRE?

I am currently running JRE 6.1. Can I delete all the old versions? These are the ones currently installed on my computer:

J2SE Runtime Environment 5.0 Update 10

J2SE Runtime Environment 5.0 Update 11

J2SE Runtime Environment 5.0 Update 4

J2SE Runtime Environment 5.0 Update 6

Java 2 Runtime Environment SE, v1.4.2_03

and of course,

Java (TM) SE Runtime Environment 6 Update 1

Thanks for the help with this.

[461 byte] By [bsm_vta] at [2007-11-27 6:10:29]