Help. I cannot get the correct value of input parameters by using RP_Input_Parameter
 

Hello everyone.
I wanna know how to access the correct value of parameters in workbench.
I creat a parameter named "Volume Flow" and registered it.
After press "Print"., the information shows as follows;

Input parameters available in udf side
.................................................. ...............................................
parameter-name current-value id-to-be-used-in-udf
.................................................. ................................................
"Volume Flow" 1.23 real-1
.................................................. ..............................................
I think this information shows that I creat the parameter successfully and the value of this parameter is 1.23
Then I tried to use a UDF to print the value on the screen to make sure that I can access the parameter.
The UDF code is:

DEFINE_INIT(initial,d)
{
real a;
a=RP_Input_parameter("real-1");
printf("a= %f\n,a);
}

The result is always "a=-0.000000" no mater how did I adjust the value of "real-1"

So have I missed something important? How can Iget the correct value of this parameter. please help.

Thanks and regards.