Strategy Input parameter validation

This is important to validate all the inputs parameter against the constraint that is defined for the variables in the given strategy. For example a user defined parameter named UserBenchmark must have a positive value.

[StrategyParameter("UserBenchmark", "0.0", "Target Spread")]
private double UserBenchmark = 0;
[StrategyParameterAttribute(("VWAPPriceTillDepth", "4", "VWAP Till Depth")]
private int VWAPTillDepth = 0;
...........
...........
protected override bool ValidateStrategyParameter(string parameterName, object paramterValue, out string errorString)
{
    errorString = string.Empty;
    bool retValue = false;
    switch (parameterName)
    {
        case "UserBenchmark" :
            retValue = paramterValue is double;
            if (retValue == false || retValue < 0)
                errorString = parameterName + " value is invalid.";
            break;
        case "VWAPTillDepth" :
            retValue = paramterValue is int;
            if (retValue == false || retValue < 0)
                errorString = parameterName + " value is invalid.";
            break;
         default:
             retValue = base.ValidateStrategyParameter(parameterName, paramterValue, out errorString);
             break;
        case StrategyInputParameter.BuyJumpPrice:
    }
 }