convert int to double with Diab C/C++

[1230]

i have no error and warning during compile, but when my program is running, there is an error in conversion int to double, like this:

double a=0.0;
int b=1;

a =(double)b; there is error..........
a=(double)b*0.1/0.1 there is error..........


the error should be a compiler option, but i can't find it.