@model string
@{
    var fieldName = Model;
}
@if (ViewData.ModelState[fieldName] != null && ViewData.ModelState[fieldName].Errors.Any())
{
    <span class="help-block field-validation-error">
        @foreach (var error in ViewData.ModelState[fieldName].Errors)
        {
            <span id="@fieldName-error" class="text-danger">@error.ErrorMessage</span>
        }
    </span>
}