Build error in eclipse

/edit:

!!PROBLEM SOLVED!!

Admin may delete this....

Hi there,

i´m working with Quartus5.0, Nios2 5.0 eval & Nios2IDE 5.0.

While first running these apps i want to execute a simple "HelloWorld" as given in the examples. I opened the Stratix1S10-small in Quartus, run the SOPC-Builder, generated all and opened Nios2IDE. Here i opened this given helloworld-project and tried to build it, what resumes to following:

**** Incremental build of configuration Debug for project hello_world_0 ****
make -s all 
Creating generated_app.mk...
Creating generated_all.mk...
C:/altera/quartus50/bin/jre/bin/java.exe: not found
make: ***  Error 1
Build completed

This specified java.exe is at this place.

Please can anybody tell me what went wrong? I think i did everything right... Are these slashes wrong(instead of backslashes)? Do i have to install java sdk?

I´m thankful for any help!