niosII simulation error

Hello

I use the modelsim 5.8 to simulation niosII with sdram control in quartus II 4.1 .

But the below errors appear.

# ** Warning: (vsim-7) Failed to open readmem file "cpu_ociram_default_contents.dat" in read mode.# No such file or directory. (errno = ENOENT) : e:/eda/altera/quartus/eda/sim_lib/altera_mf.v(23352)# Time: 0 ps Iteration: 0 Instance: /test_bench/DUT/the_cpu/nilO0ll# # ************************************************************# This testbench includes an SOPC Builder Generated Altera model:# 'sdram_test_component.v', to simulate accesses to SDRAM.# Initial contents are loaded from the file: 'sdram.dat'.# ************************************************************

who can help me ?

Thank you!