function checkDot(str){
}
function checkNum(str)
{
var firstNumber;
var secondNumber;
var dotFlag=false;
        for (var i = 0; i < str.length; i++) {
                var ch = str.substring(i, i+1)
                if (ch == "+" || ch == "/" || ch == "-" || ch == "*" ) {
                   firstNumber=str.substring(0,str.indexOf(ch));
	secondNumber=str.substring(str.indexOf(ch)+1,str.length);
	firstNumber=firstNumber.substring(firstNumber.indexOf('.'),firstNumber.lastIndexOf('.'));
	secondNumber=secondNumber.substring(secondNumber.indexOf('.'),secondNumber.lastIndexOf('.'))
//		alert('First Number');		
//		alert(firstNumber);
//		alert('Second Number');
//		alert(secondNumber);
		if(firstNumber != 0 ){
//		alert('Evry thing not okay with number 1');
		alert('Invalid Pattern with first Number');
		//break;
		return false;
		}
	                    if(secondNumber != 0){
//		alert('Evry thing not okay with number 2');
		alert('Invalid Pattern with second Number');
//		break;
		return false;
		}
		
  }
        }
        return true
}

function checkOperator(str,operator)
{
var opr=operator;
        for (var i = 0; i < str.length; i++) {
                var ch = str.substring(i, i+1)
               if (ch == "+" || ch == "/" || ch == "-" || ch == "*"    ) {
		return false;
		
			}
		}
return true;
	}
function backSpace(str)
{
document.Calc.Input.value=str.substring(0,str.length-1);
	}