function first(){
document.calc.dd.value+="1";
}
function sec(){
document.calc.dd.value+="2";
}
function third(){
document.calc.dd.value+="3";
}
function fourth(){
document.calc.dd.value+="4";
}
function fifth(){
document.calc.dd.value+="5";
}
function sixth(){
document.calc.dd.value+="6";
}
function seven(){
document.calc.dd.value+="7";
}
function eight(){
document.calc.dd.value+="8";
}
function plus(){
document.calc.dd.value+="+";
}
function minus(){
document.calc.dd.value+="-";
}
function divid(){
document.calc.dd.value+="*";
}
function sub(){
document.calc.dd.value+="/";
}
function zeroo(){
document.calc.dd.value+="0";
}
function equal(){
document.calc.dd.value= eval(calc.dd.value);
}
function clr(){
document.calc.dd.value = "";
}
