System.Format Exception: input string was not in a correct format

Server error in '/' Application
Input string was not in a correct format.
Description : An unhandled exception occurred during the execution of the current web request.Please review the stack trace for more information about the error and where it originated in the code.
Exception details: System.FormatException: Input string was not in a correct format.
Source error:
Line 211:
Line 212: JobClass objJob = new JobClass();
Line 213: int AppID = objJob.AddJobApplication(JobID, txtName.Text, txtLastName.Text, rdGender.SelectedValue, DOB,


Source File : d:\FirstsourceCorporatesSite\WebPages\FSWebsite\FirstSource\submit_resume.aspx.cs Line: 213
Stack Trace:
[FormatException: Input string was not in a correct format.]
System.Number.StringToNumber (String str , NumberStyles options , NumberBuffer& number , NumberFormatInfo info , Boolean parseDecimal) +2725283
System.Number.ParseInt32(String s , NumberStyles style , NumberFormatInfo info) +102
System.Convert.ToInt32(String value) +68
submit_resume.SaveApplicationDetails() in d:\FirstsourceCorporatesSite\WebPages\FSWebsite\FirstSource\submit_resume.aspx.cs  :213
submit_resume.btnSubmit_Click(Object sender, EventArgs e) d:\FirstsourceCorporatesSite\WebPages\FSWebsite\FirstSource\submit_resume.aspx.cs  :129
System.Web.UI.WebControls.Button.OnClick(EventArgs e) +105
System.Web.UI.WebControls.Button.RaisePostBackEvent(String eventArgument) +107
System.Web.UI.WebControls.Button.System.Web.UI.IPostBackEventHandler .RaisePostBackEvent(String eventArgument) +7
System.Web.UI.Page.RaisePostBackEvent(IPostBackEventHandler sourceControl , String eventArgument) +11
System.Web.UI.Page.RaisePostBackEvent(NameValueCollection postData) +33
System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint) +5102


Version information : Microsoft.Net Framework Version: 2.0.50727.832; ASP.NET Version:2.0.50727.832