How do I heap sort alphabetically?

I have a heapsort function which i've used to sort a list of integers. How do I adapt this function to sort a list of strings alphbetically?

My sort function is:

Code:

`int temp, item, j;`

for(int k=i-1; k>0; k--)

{

for(int i=0; i<=k; i++)

{

item=value[i].first_name;

j=i/2;

while (j>0 && value[j].first_name<item)

{

value[i].first_name=value[j].first_name;

i=j;

j=j/2;

}

value[i].first_name=item;

}

temp=value[1].first_name;

value[1].first_name=value[k].first_name;

value[k].first_name=temp;

}