View Compilation Error

0_0_2262711_23499.c: In function `main':
0_0_2262711_23499.c:12: error: invalid application of `sizeof' to incomplete type `ballon' 
0_0_2262711_23499.c:25: error: `number_of_color' undeclared (first use in this function)
0_0_2262711_23499.c:25: error: (Each undeclared identifier is reported only once
0_0_2262711_23499.c:25: error: for each function it appears in.)
0_0_2262711_23499.c:33: error: `color' undeclared (first use in this function)