import math

def calculate_square_root():
    user_input = input("Enter a number to calculate its square root: ")
    
    try:
        # Try to convert the input to a float
        number = float(user_input)
        
        if number < 0:
            # Handle negative numbers
            print("Error: Cannot calculate the square root of a negative number.")
        else:
            # Calculate and display the square root
            square_root = math.sqrt(number)
            print(f"The square root of {number} is {square_root}.")
    
    except ValueError:
        # Handle non-numeric input
        print("Error: Please enter a valid numeric value.")

# Run the function
calculate_square_root()