请大家看看我这段代码有什么错误
错在哪里
怎么改正
谢谢了
……

#include"stdio.h"
main()
{
int score;
char grade;
printf("\nplease input a student score:");
scanf("%f",&score);
if(score>100||score<0)
printf("\ninput error!");
else
{if(score>=90)
grade='A';
else
{if(score>=70)
grade='B';
else
{if(score>=60)
grade='C';
else grade='E';
}
}
}
printf("\nthe student grade:%c",grade);
}