Can we make a random choose from a alphas chars ?

srand(time(NULL));
rand()%z   // from A  to z 
// Sure wrong  wiz errors  .. 
//so which way i can use  ? Converting to  Assci Code and choose 
// randomly  form the Numbers which are from 65  to  90 ??

The mod operator works on integers, not letters. Put the letter in single quotes and it will work because that will change the letter to an integer rand() % 'z' But that probably will not be what you are looking for.

read this tutorial